Report 2005 DIPARTIMENTO DI CHIMICA E FISICA PER L'INGEGNERIA E PER I MATERIALI - Unibs
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DIPARTIMENTO DI CHIMICA E FISICA
PER L’INGEGNERIA E PER I MATERIALI
Report 2005
Università degli Studi di Brescia
PRESENTATION
The department of Chemistry and Physics for Engineering and for Materials belongs to Faculty of
Engineering of the University of Brescia.
It is composed of three sections: Section of Fundamental Physics, Section of Physics of Matters and
Section of Material Science and Technology.
The present Report describes the research activities carried out at the Department of Chemistry and
Physics for Engineering and for Materials Laboratory, also in collaboration with other academic and
industrial institutions until the end of 2005.
The present Report consists of tables, which resume at a glance all the data on the structural resources
and scientific / technical activity of the department, and a textual part, which describes the main active
lines of three sections in which the department is divided.
A CNR-INFM (Consiglio Nazionale delle Ricerche – Istituto Nazionale per la Fisica della Materia)
Laboratory, the only CNR site in Brescia, operates inside the Section of Physics of Matters.
The Department has stipulated conventions with INFN (Istituto Nazionale di Fisica Nucleare), INFM, and
INSTM (Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali).
2
CONTENTS
1 GENERAL INFORMATION..........................................................................................................4
1.1 STRUCTURAL DATA AND RESOURCE................................................................................4
1.1.1 GENERAL INFRASTRUCTURES...............................................................................4
1.1.2 CONNECTED INTERNATIONAL LABORATORIES FOR RESEARCH.................................6
1.1.3 HUMAN RESOURCES............................................................................................7
1.2 SECTIONS AND RESEARCH LINES....................................................................................9
1.2.1 SECTION OF FUNDAMENTAL PHYSICS....................................................................9
1.2.2 SECTION OF PHYSICS OF MATTERS.....................................................................20
1.2.3 SECTION OF MATERIALS SCIENCE AND TECHNOLOGY...........................................32
1.3 EXTERNAL RELATIONS.................................................................................................46
2 INSTITUTE RESOURCES.........................................................................................................49
2.1 BUDGET.....................................................................................................................49
3 DEPARTMENT ACTIVITY BETWEEN 2001-2005...........................................................................50
3.1 SCIENTIFIC AND TECHNICAL PRODUCTION.....................................................................50
3.1.1 SCIENTIFIC PRODUCTION IN ISI-INDEXED JOURNALS..........................................50
3.1.2 REPORTS AND INVITED CONFERENCES PRESENTED AT CONGRESS AND
PARTECIPATION AS EDITORS OR ADVISORS TO SCIENTIFIC PRODUCTIONS.....................51
3.1.3 APPLICATION FOR AND GRANTING OF PATENTS....................................................53
3.1.4 INTERNATIONALIZATION OF RESEARCH ACTIVITIES.............................................53
3
1 GENERAL INFORMATION
1.1 STRUCTURAL DATA AND RESOURCE
1.1.1 GENERAL INFRASTRUCTURES
Table 1. Total area and space distribution (m2)
DEPARTEMENT Laboratoires Offices Total
Administration 30 30
Section of Fundamental Physics 70 120 190
Section of Physics of Matters 150 90 240
Section of Materials Science and Technology 250 100 350
Total 810
Table 2. Equipments acquired in last years.
EQUIPMENTS Year of Purchase COST( K euro ) RESPONSIBLE
Section of Physics of Matters
Sputtering plant 2001 250 Comini
SEM-FEG (LEO 1525) 2004 230 Ferroni
Analysis EDX for SEM 2004 65 Ferroni
CCD+Monochromator+Ar
laser for PL 2001 50 Baratto
measurements
Nano-manipulator for
2005 70 Ferroni
SEM
Semi-automatic Wedge
2001 35 Baratto
bonder
AFM with dip - pen tool
2002 120 Ponzoni
for nanolitography
Step Profiler 2003 35 Comini
Functional
characterization 2000 80 Baratto
equipment
Functional
characterization 2003 90 Ponzoni
equipment
Kelvin Probe 1999 20 Baratto
Spin-coater 1999 20 Poli
Cluster PC 2005 15 Pardo
Electronic Nose 2004 30 Falasconi
Section of Materials Science and Technology
Mechanical and rheological analysis
Universal dynamometer
for static mechanical 2003 50
testing (Instron Ltd, UK)
4
EQUIPMENTS Year of Purchase COST( K euro ) RESPONSIBLE
Servo-hydraulic machine
for Dynamic Mechanical 2005 50
Testing (Instron Ltd, UK)
Instrumented Pendulum
for Impact tests (Ceast 2002 30
SpA, I)
Dynamic Mechanical
Thermal Analyzer DMTA 2000 20
(Polymer Lab Ltd, UK)
Instrument for creep
2002 -
tests on polymers
Twin-bore Capillary
Rheometer (Ceast SpA, 2004 100
I)
Thermal and Physico-Chemical Analysis
Differential Scanning
Calorimetry (DSC) 1988 20
(Perkin-Elmer)
Modulated DSC (TA
2003 60
Instruments)
Infrared Spectrometry
1991 15
(FTIR) (Jasco)
Nuclear Magnetic
Resonance (H1-NMR) 1988 -
(Varian)
UV-vis
Spectrophotometry 1992 5
(Perkin-Elmer)
Gel Permeation
1988 - 2002 15
Chromatography (GPC)
Gas Chromatography
1995 10
(Perkin-Elmer)
Travelling Optical
2004 6
Microscopy (Leica)
Processing Techniques
Brabender Mixer
2005 40
(Brabender, G)
Single-screw Extruder
2004 -
(Fuji, J)
Material and Specimen Preparation
Equipments for specimen
preparation (Ceast SpA, 2002 - 2005 15
I)
Equipments for synthesis
1988 - 2005 30
and chemical analyses
Computational techniques
Computer-aided analysis
(CAA) for plastics
processing. Flow analysis 2005 150
family of programs
(MoldFlow).
5
1.1.1.1 COMPUTER INFRASTRUCTURE
The Departments owns a local area network, with some servers belonging to different Sections.
1.1.2 CONNECTED INTERNATIONAL LABORATORIES FOR RESEARCH
CERN, Geneve, Switzerland.
JINR, DUBNA, Russia.
Key lab of CLAMS of Education Ministry, Jilin University, China.
Universitat Autonoma de Barcelona, Barcelona, Spain.
European Laboratory for Nonlinear Spectroscopy, Firenze, Italy.
INFN Laboratori Nazionali Legnaro, RBS measurements (Rutherford Backscattering Spectroscopy)
IMM-CNR Sezione di Bologna, transmission electron microscopy.
6
1.1.3 HUMAN RESOURCES
Table 3. Human resources.
NAME CATEGORY TITULATION
Administration
Gilberto Fattore Administrative director Administrative
Battista Mariotti Administrative
Alfonsa Russo Administrative
Section of Fundamental Physics
Evandro Lodi Rizzini Scientific Responsible – Director of the Dept. Full Professor
Andrea Bianconi Associate Professor
Luca Venturelli Associate Professor
Maurizio Corradini Researcher
Nicola Zurlo Researcher
Giorgio Di Giovambattista Technician
Marco Leali Research assistant
Aldo Mozzanica PhD student
Section of Physics of Matters
Scientific Responsible – vice-Director of the
Giorgio Sberveglieri Full Professor
Dept.
Guido Faglia Associate Professor
Maurizio Artoni Associate Professor
Elisabetta Comini Researcher
Matteo Ferroni Researcher
Camilla Baratto Research assistant
Matteo Falasconi Research assistant
Nicola Poli Technician
Andrea Ponzoni Research Fellowship
Marco Vezzoli PhD student
Sebastiano Bianchi PhD student
Marco Picinelli Research Fellowship
Matteo Pardo Researcher CNR-INFM
Alberto Vomiero Researcher CNR-INFM
Rosita Nodari Administrative CNR-INFM
Section of Materials Science and Technology
Theonis Riccò Scientific Responsible Full Professor
Fabio Bignotti Associate Professor
Maurizio Penco Associate Professor
Luciana Sartore Associate Professor
Francesco Baldi Researcher
Stafano Pandini Researcher
Giorgio Ramorino Researcher
Isabella Peroni Technician
7
NAME CATEGORY TITULATION
Gloria Spagnoli Technician
Stefania della Sciucca Post-Doc. fellowship
Giacomo Borsarini Research fellowship
Francesco Branca Research fellowship
Andrea Tononi Research fellowship
Ottavia De Feo PhD student
Andrea Sassi PhD student
8
1.2 SECTIONS AND RESEARCH LINES
1.2.1 SECTION OF FUNDAMENTAL PHYSICS
Activity:
• Nuclear Physics
• Physics of Elementary Particles
• Atomic Physics
• Technologies of Fundamental Physics
2005 I.N.F.N. funds : 228.500 €
Site of research C.E.R.N. - Geneva
9
Research staff
Prof. Evandro Lodi Rizzini (head)
• Prof. Andrea Bianconi
• Prof. Luca Venturelli
• Maurizio Corradini
• Nicola Zurlo
• Marco Leali
• Aldo Mozzanica
Technical Staff:
• Giorgio
Di Giovambattista
1.2.1.1 HISTORICAL INTRODUCTION
The Section of Fundamental, Nuclear and Elementary Particles Physics of the Department is also the
center of the National Institute for Nuclear Physics, I.N.F.N., through the Brescia CONNECTED GROUP.
This works on the base of the convention
stipulated with the Universita' Statale di
Brescia in 2002 and represents the
acknowledgment of the National Agency for
this field of Physics to the research work in
the field of the Nuclear physics and
Elementary Particles carried out by Prof.
Evandro Lodi Rizzini and various collaborators
from academic year 1980-81, when the
Università Statale di Brescia had not yet been
instituted and the Faculty of Engineering was
connected with the Polytechnic of Milan. In
10academic year 1980-' 81 the activity at C.E.R.N. (European Organization for Nuclear Research) in
Geneva was started.
The first experiment (PS179), developed within an International Collaboration, marks the beginning of
the search in the field of the Nuclear Physics for the measurement of the processes of the annihilation of
Antiprotons on Nuclei. This field is moreover the object of the search that always to the CERN of
Geneva, has been approved from the Research Board of the Center the 2 june 2005.
From some hundreds of Mev of experiment PS179, the antiprotons initial energy will decrease to less
than 1 keV with the new experiment ASACUSA (AD3), with a jump of five orders of magnitude in
reducing the energy of the particle projectile (Antiproton).
After these 25 years of search in this field, then the group will achieve to measure fundamental physics
quantities in the process of annihilation of Antiproton on Nuclei for values of its kinetic energy
corresponding to the possible starting of capture by Atoms and Molecules.
In the famous photogram filmed in 1983 with the Streamer Chamber of PS179 Collaboration, it is
possible to see the annihilation of the antiproton on a neon nucleus inducing the emission of a positive
pion, π+, with the successive decay in a positive muon, μ+, which decays in the positron, e+. The three
particles are clearly visible from the succession of their tracks which appear as curves lines since these
charged particles move in an magnetic field (intensity = 0.5 tesla) orthogonal to the plane of the figure.
This photogram introduces to the search in the field of Elementary Particles undertaken from 1985
within of the international Collaboration PS201, OBELIX, having for main goal the characterization of the
possible particle made of only gluons (mediators of the force between quarks) or of gluons and light
quarks formed in the antiproton-proton annihilation. This last search has terminated in 2004 with
important results and has been characterized by the proposed innovative choice from Prof. Lodi Rizzini
to use various hydrogen targets at very different densities to obtain the necessary information from all
possible the various channels of annihilation of the antiproton at rest on proton.
This methodology has carried the group to begin the activity in the field of the Atomic Physics, activity
that would have lead to the Hydrogen Antiatom production still at CERN of Geneva in August 2002, for
the first time in the science history, thanks to International Collaboration AD1 called ATHENA. Prof. Lodi
Rizzini has been the responsible of the Italian part of this Collaboration from the beginning, in 1995,
until to 2001.
11AD1 - ATHENA APPARATUS
ANTIIDROGEN ANNIHILATION
1.2.1.2 NUCLEAR PHYSICS
The experimentation with antiprotons at the Low Energy Antiproton Ring (L.E.A.R.) of the CERN begins
in the within of the International Collaboration PS179 using a Streamer Chamber filled up with neon or
helium in order to visualize the traces of electrically charged particles involved in the collision of an
antiproton p with the nucleus of the filling gas. This detector of the dimensions of 90x70x18 cm3 was
placed in a magnetic field of 0.5 tesla in order to measure the momentum of charged particles through
their curvature and to identify their nature. The kinetic energies of the p projectile have been 180MeV,
49 Mev, 20 Mev according to the performances of decelerator L.E.A.R. in the course of the years. Below
12these energies the Glauber (Nobel prize 2005) approsimation is no more valid. Beyond that for the
various nuclear reactions to these energies, the interaction of the antiproton with the nuclei of the gas
target has been studied also after its capture at "rest". This was obtained by inserting suitable layers of
material across the line of the p beam before the detector. The first phase of the researches at
L.E.A.R. terminated in 1985 and the decelerator was modified in order to obtain energies of antiprotons
still lower, until to 5.3 MeV; in the successive phase, the Prof. Lodi Rizzini realized with a new and
original method the measure of the collision cross section (probability) of the annihilation of antiprotons
on helium nuclei at 1 MeV, by far at that time the one at the lowest p energy. This first measure will
open the road to the attempts to obtain the same information in the
antiproton interaction with other nuclei, starting from hydrogen, (i.e.
the proton p). Inside the PS201 collaboration OBELIX this goal has
been achieved, at least partially, with the amazing discovery that the
annihilation cross section of antiprotons of approximately 1 MeV
kinetic energy has the same value obtained for the nucleus of hydrogen also for deuterium and He 4. This
unexpected result has been otherwise confirmed, in the case of deuterium, by the study of the related
antiprotonic atom in the fundamental state.
Also the CERN Courier of July/August 2000 has dealt with this situation "amazing" and antithetical to a
"geometric" vision of the size of different nuclei.
This observation has led also to "interpretative" articles among which we like to signal
13• A. Bianconi et al., Limits on the low-energy antinucleon-nucleus annihilations from the
Heisenberg principle Europhysics Letters 54, 443 (2001)
The Brescia group proposed therefore to the ASACUSA Collaboration to complete and to extend to the
lowest possible energies the study of the antiproton annihilation on nuclei. This scientific program
became a part of the one of the Collaboration after the approval of the SPSC Committee of the CERN in
June 2005. The related data-taking will start from 2006 at 5 MeV energies The data-taking at energies
of 1 KeV and lower is foreseen starting from 2007.
1. E. Lodi Rizzini et al., Antiproton-Nucleus annhilation at very low energies down to capture to be
printed by American Institute of Physics (2005)
2. ASACUSA Collaboration CERN-SPSC 2005-002; SPSC-97-19 Spectroscopy and Collisions Using
Ultra Slow Antiprotons.
In fig. the proposed experimental setup.
ASACUSA Collaboration List
• Austria
M. Carnelli, H. Fuhrman, J. Marton, E. Widmann, J. Zmeskal
Stefan Meyer Institut für subatomare Physik, Boltzmanngasse 3, 1090 Vienna,
Aust
• Denmark
H. Knudsen, P. Kristiansen, U. I. Uggerhoj
Department of Physics and Astronomy, University of Aarhus,
DK-8000 Aarhus C, Denmark
S.P. Møller
Institute for Storage Ring Facilities (ISA), University of Aarhus,
DK-8000 Aarhus C, Denmark
H.H. Andersen
Niels Bohr Institute, Blegdamsvej 17,
DK-2100 København Ø, Denmark
14• Germany
T. Ichioka
MPI für Kernphysik (MPI-K), Heidelberg, Saupfercheckweg 1, 69117
Heidelberg, Germany
• Hungary
D. Barna, D. Horváth, P. ZalánResearch Institute for Particle and Nuclear
Physics, H-1525 Budapest, Hungary
B. Juhász, K. Tökési
Institute of Nuclear Research (ATOMKI), H-4001 Debrecen, Hungary
• Italy
M. Corradini, M. Leali, E. Lodi Rizzini, L. Venturelli, N. Zurlo
Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, Università di
Brescia, 25123 Brescia, Italy
• Japan
A.J. Dax, J. Eades , R.S. Hayano, T. Ishikawa, K. Gomikawa, N. Ono, W. Pirkl,
T. Yamazaki
Department of Physics, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
K. Komaki, Y. Nagata, H.A. Torii, Y. Yamazaki
Institute of Physics, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo
153-8902, Japan and Atomic Physics Laboratory, RIKEN, Wako 351-01, Japan
Y. Kanai, N. Kuroda, A. Mohri, N. Oshima, M. Shibata, V. Varentsov, M. Wada
Atomic Physics Laboratory, RIKEN, Wako 351-01, Japan
• Switzerland
M. Hori
CERN, H-1211 Genève 23, Switzerland
• United Kingdom
M. Charlton
Department of Physics, University of Wales Swansea, Singleton Park, Swansea,
SA2 8PP, UK
R. McCullough
Dept. of Pure and Applied Physics, Queen's University Belfast University Road,
Belfast BT7 1NN, UK
Meanwhile the Brescia Group partecipated in the nuclear physics program of the DUBTO experiment at
JINR Phasotron (Dubna, Russia), using beams of positive and negative pions and a streamer chamber
equipped with CCD telecameras. The analysis of the events collected on He4 is in progress but
unfurtunately a serious fire accident broke out in the accelerator whose running is in doubt. This will
involve the temporary suspension of PAINUC program.
1.2.1.3 PHYSICS OF ELEMENTARY PARTICLES
In the field of Elementary Particles the Group of Brescia has produced important contributions within
the experiment PS201 OBELIX, an international collaboration formed in 1985 in order to operate at
L.E.A.R. of the CERN, with the aim of characterizing the mesonic systems with light quarks or with
15gluons, formed especially by the annihilation of the antiproton at rest on hydrogen, or the antineutron at
low kinetic energies again on hydrogen.
The conclusive article published twenty years after the beginning of the Collaboration underlines how
the technique of the various densities used in order to stop antiprotons in hydrogen was decisive to
have the control of the partial waves, that contribute to the formation of mesonic states in the pp
annihilation at rest. This work played an important role in the phenomenological description within the
QCD (Quantum Chromo Dynamics) of the decays of the produced mesons. Tens of articles have
illustrated the information obtained from the analysis of the several channels of N N annihilation
studied. Below we mention the last and conclusive articles.
• M. Bargiotti et al., Coupled channel analysis of π+π-π0, K+K-π0 and K±K0sπ± from p p
annihilation at rest in hydrogen targets at three densities Eur. Phys. J. C 26, 371 (2003)
• M. Bargiotti et al., Dynamical selection rules from p p annihilation at rest in three meson final
states Eur. Phys. J. C 35, 177 (2004)
PS 201 - APPARATO OBELIX
1.2.1.4 ATOMIC PHYSICS
The research in the Physics of Elementary Particles has been the central topic of the Collaboration
PS201, OBELIX. In order to use hydrogen targets with densities till one thousandth of the usual one,
where the annihilations happen at rest in hydrogen mainly in P wave, it was necessary to study the
energy loss of antiprotons in this gas from the beginning kinetic energy of some MeVs to the capture at
some eVs, i.e. about 6 orders of magnitude. The Group of Brescia has introduced therefore a new
methodology for the appraisal of stopping power (the energy loss for braking), using the space-time
reconstruction of the annihilations of antiprotons with the resolution of the OBELIX apparatus.
This work has allowed to obtain the only existing measures for the two simples structures: the hydrogen
molecule (H2) and the simple helium atom of helium (He) in the whole range of energy. The most
16important results have been the matter of two papers on Physical Review Letter in 1995 and in 2002,
while the whole treatment is collected in about ten articles, whose we report the conclusive ones.
1. A. Bianconi et al., Antiproton slowing down, capture, and decay in low-pressure helium gas
Phys. Rev. A 70, 032501 (2004)
2. E. Lodi Rizzini et al., Antiproton spopping power in He in the energy range 1-900 KeV and the
Barkas effect Phys. Lett. B 599, 190 (2004)
3. E. Lodi Rizzini et al. Barkas effect for antiproton stopping in H2 Phys. Rev. Lett. 89, 18 (2002)
In the picture the stopping power of the antiproton in hydrogen is drawn with continuous line, while that
one of the proton is marked with dotted line.
In this field the Group of Brescia has also supplied important and sometimes unique informations on the
length of the "cascade" which brings the antiproton from the quantic numbers (n,l) of capture followed
by the annihilation on the nucleus, proton (p) or the alpha particle (α), respectivly in the case of
hydrogen or helium. Also this sector has been illustrated with about ten articles on the most important
reviews. These activities of Atomic Phisycs have been at the base of the choice to activate the research
for the production of antiatoms of hydrogen H. The relative international collaboration was established
in 1995 and was called ATHENA, labelled with the acronym AD1 by the CERN. The data taking took
place in 2002, 2003 and 2004. The clear indication of antihydrogen production appeared in August 2002
and was communicated to the world scientific community on September 18th, when an article (sent by
the collaboration on August 28th) appeared on the scientific journal Nature.
17In the following articles published in Physical Review Letters and in other leading international journals
are being published the results of the analysis aimed at characterizing the antihydrogen atom p e+
formation process starting from the superposition of positron (e+) and antiproton p clouds in a
suitable trap. In the following picture, we reproduce the characteristic signature of the antihydrogen
atom production (Nature, september 2002). You can observe the peculiar peak of the antiproton
annihilation events, coming from the negative nuclei of the antihydrogen atoms, in temporal coincidence
with the relative positron annihilation happening on an electron of the matter costituting the trap wall.
In this trap antiprotons and positrons are superimposed in order to make them bind and form
antihydrogen. The positron-electron (e+ e-) annihilation feature is the opening angle between the two
511 keV photons of 180 degrees, i.e. its cosine equals -1.
1. L. V. Jørgensen et al., New Source of Dense, Cryogenic Positron Plasmas Phys. Rev. Lett. 95,
025002 (2005)
2. N. Madsen et al., Spatial Distribution of Cold Antihydrogen Formation Phys. Rev. Lett. 94,
033403 (2005)
3. M. Amoretti et al., Dynamics of Antiproton Cooling in a Positron Plasma During Antihydrogen
Formation Phys. Lett. B 590, 133-142 (2004)
4. M. C. Fujiwara et al., Three-Dimensional Annihilation Imaging of Trapped Antiprotons Phys.
Rev. Lett. 92, 065005 (2004)
5. M. Amoretti et al., Antihydrogen production temperature dependence Phys. Lett. B 583, 59-67
(2004)
6. M. Amoretti et al., High rate production of antihydrogen Phys. Lett. B 578, 23-32 (2004)
7. M. Amoretti et al., The ATHENA antihydrogen apparatus Nucl. Inst. Meth. Phys. Res. A 518,
679-711 (2004)
8. M. Amoretti et al., Positron Plasma Diagnostic and Temperature Control for Antihydrogen
Production Phys. Rev. Lett. 91, 055001 (2003)
9. M. Amoretti et al., Complete Nondestructive Diagnostic of Nonneutral Plasmas Based on the
Detection of Electrostatic Modes Phys. Plasma 10, 3056 (2003)
1810. M. Amoretti et al., Production and detection of cold antihydrogen atoms Nature 419, 456
(2002)
1.2.1.5 Technologies of Fundamental Physics
During the eighties our Group realized a new technique, digitizer tools based, to visualize the images
collected by the streamer-chamber of PS179 experiment at C.E.R.N.. This technique let us increase the
speed in analyzing photographic films and so in studying antitprotons annihilation events.
At the end of the eighties our Group looked after the realization of the gas flowing system for the
detectors of PS201 Obelix experiment, as well as the systems for vacuum and for target-gases control.
At the present, for ASACUSA experiment, our Group planned and is realizing a vertex detector based on
scintillating fibers, that reconstructing the tracks of the pions emitted in annihilation events will let us
study annihilation cross-sections of different target gases for very low energy antiprotons. To flow the
target gas our Group planned and realized a differential pressure line that will allow us to range from
normal pressure to UHV, optimizing target densities.
191.2.2 SECTION OF PHYSICS OF MATTERS
Research Staff:
• Giorgio Sberveglieri
• Guido Faglia
• Maurizio Artoni
• Elisabetta Comini
• Matteo Ferroni
• Camilla Baratto
• Matteo Falasconi
• Nicola Poli
• Andrea Ponzoni
• Marco Vezzoli
• Sebastiano Bianchi
• Matteo Pardo
• Alberto Vomiero
• Marco Picinelli
• Rosita Nodari
The Section of Physics of Matters is composed by SENSOR Lab, that originates from the Gas Sensor Lab
(GSL) active since 1987. SENSOR is a CNR laboratory and is the only CNR site in Brescia. The Director
of SENSOR is Prof. Giorgio Sberveglieri and the secretary is Dr. Rosita Nodari.
The main scientific tasks of SENSOR are the preparation and functional characterisation of gas/flavour
sensors based on semiconducting (SC) thin films and the development of an Artificial Olfactive Systems
(AOS). The Physics of Matters section comprises also a sizeable theoretical activity mainly devoted to
the study of quantum coherence effects in semiconductors. Over the past two years much effort has
20been devoted, e.g., to the study of coherent control of light transmission in copper chloride and on
tunable tunneling induced quantum interference in specific low dimensional structures.
1.2.2.1 Highlights
Plenary talk “Quasi mono-dimensional metal oxide semiconductors as the new generation of gas
sensors” G. Sberveglieri , G. Faglia, C.Baratto, E. Comini, M. Ferroni, A Ponzoni. 2nd International
Workshop on Nano & Bio-Electronics Packaging, March 22-23, 2005, Atlanta, Georgia, USA
The Section Physics of the Matter has been the most productive institution presenting 8 communications
at the IEEE Sensor Conference held in Irvine (California ) last October which has been the largest
conference on sensors in 2005
“Adsorption effects of NO2 at ppm level on visible photoluminescence response of SnO2” nanobelts,
G.Faglia, C.Baratto, G.Sberveglieri, M.Zha, A.Zappettini, Applied Physics Letters, 86 (2005) 011923
As fast-approaching scientific event for 2006, the Section of Physics of Matters will organize in Brescia
the XI International Meeting on Chemical Sensors – IMCS. This Meeting is one of the most important
meeting in the field of chemical sensors that take place every two years. The general conference
chairman is Prof. Giorgio Sberveglieri.
1.2.2.2 Introduction to applied research activity
Conductometric semiconductor thin films are the most promising devices among solid state chemical
sensors, due to their small dimension, low cost, low power consumption, on-line operation and high
compatibility with microelectronic processing. The progress made on Si technology for micromachining
and microfabrication foreshadows the development of low cost, small size and low power consumption
devices, suitable to be introduced in portable instruments and possibly in biomedical systems.
The materials for chemical sensing that are investigated cover a wide spectrum of metal oxides (MOX):
SnO2, In2O3, WO3, MoO3, TiO2, Ga2O3, and several mixed oxides like SnO2-In2O3, TiO2-Fe2O3 and TiO2-
WO3. The electrical and functional properties of these layers are studied both with AC, DC and work
function measurements towards environmental and polluting gaseous species.
The sensing layers are prepared by physical vapour deposition (PVD) techniques, in particular RF
magnetron sputtering, which are easily scalable on the industrial scale; these layers are deposited both
on alumina and silicon micromachined substrates.
The fundamental sensing mechanism of semiconductor
gas sensors relies on a change in electrical conductivity
due to the interaction process between the surface
complexes and the gas molecules to be detected. The
effects of the microstructure, namely, ratio of surface
area to volume, grain size and pore size of the metal
oxide particles, as well as film thickness of the sensor are
well recognized. Lack of long-term stability and selectivity Sensor mounted on TO-8
has until today prevented a widespread diffusion of this case for electrical
type of sensors. measurements
A new research horizon in the field of gas-sensing has been recently opened towards nanostructured
systems with reduced dimensionality like semiconducting quantum nanobelts, porous silicon, and carbon
21nanotubes. Nanobelts and porous silicon show visible photoluminescence that is reversibly affected by
gas environment. For these materials an optical sensor is under study.
The progress of the nanolitographic technology and the improvement of preparation techniques of the
last decades caused a remarkable reduction of the size producing mesoscopic devices with a structure
that is small with respect to the macroscopic dimension where the Boltzmann transport equation holds.
The quantum confinement of these mesoscopic structures modifies completely the transport and optical
properties of the material and increases the role of the surface states in the sensor response due to the
surface/volume ratio. A new theory of the gas-materials interactions should be developed for the
mesoscopic structures with promising sensor properties.
The last decade has witnessed an increasing interest in the study and realization of Artificial Olfactory
Systems, or Electronic Noses (EN), which can be useful in application domains like environmental
monitoring and food processing control. ENs analyze gaseous mixtures for discriminating between
different (but similar) mixtures and, in the case of simple mixtures, quantifying the constituents'
concentration. The development of an instrument capable of recognizing odors is the ultimate
applicative justification for the study of chemical sensors.
In the last years, the SENSOR Lab developed successive versions of the Electronic Nose Pico-X
(X=1,2,3). Pico has been used in the agriculture and food field (e.g. coffee quality control), for
environmental monitoring (e.g. quantification of malodors in landfill sites) and for the detection of TNT.
A collaboration with a medium size company, SACMI (Imola - Bologna), started in 2001 to engineer and
commercialize the research findings coming out from the SENSOR Lab. In 2003 the first commercial EN,
the SACMI EOS 835 olfactory system, based on the Pico-2 EN from the Sensor Lab, was put on the
market.
One necessary component of the EN is data analysis. Therefore a research line on learning from data
has been developed, comprising explorative analysis, preprocessing and supervised learning (with linear
techniques, neural networks)
Below we describe in detail the two research fields:
sensors
electronic nose
1.2.2.3 Sensors
The SENSOR Lab is fifteen-year experienced in preparing semiconductor metal oxides as thin films by
Physical Vapour Deposition (PVD) techniques, in particular RF magnetron sputtering, which are easily
scalable on the industrial scale; these layers are deposited both on alumina and silicon micromachined
substrates.
Although a large number of different oxides have been investigated for their gas sensing properties,
commercially available gas sensors are mainly made of SnO2 in the form of thick film, porous pellets or
thin films.
Lack of long term stability and selectivity has until today prevented a widespread diffusion of this type
of sensors. To improve the state of the art of metal oxide gas sensing technology the approach is
twofold: prepare innovative binary and ternary SC thin films with a synergetic effect related to stability
and selectivity and to make the way towards a new generation of solid state mesoscopic chemical
sensors obtained by innovative deposition techniques and lithographic patterning.
The functional properties of the prepared materials - together with innovative systems like Porous
Silicon and Carbon Nanotubes developed by groups with which the SENSOR Lab collaborates - are the
topic of the research line Optical, electrical and functional properties of SC metal oxides, Porous Silicon
22and Carbon Nanotubes in a gaseous environment . The feedback from this activity is strategic for the
choice of the most promising systems and the optimisation of materials preparation conditions.
Of course the development of a new generation of nanoscale gas sensitive materials requires innovative
approach based on a fundamental understanding of the gas sensitivity mechanism. The majority of the
literature works done on the gas sensitive nanocrystalline semiconductor oxides aim to improve the
functional parameters: sensitivity, selectivity, response, etc. In contrast, fundamental studies of the
mechanism of nanocomposite interaction with gas phase are lacking.
Solid state mesoscopic gas sensors
The most recent research has been devoted towards nanostructured oxides since reactions at grain
boundaries and complete depletion of carriers in the grains can strongly modify the material transport
properties. Unfortunately the high temperature required for the surface reactions to take place induces
a grain growth by coalescence and prevents the achievement of stable materials.
The objective of the activity is the preparation of a new generation of solid state mesoscopic chemical
sensors with superior performances. The sensors are fabricated by nanoengineering techniques through
optical, electronical and x-ray nanolithography or by selective removal of materials and advanced
techniques of preparation. New quantum confined mesoscopic devices - quantum wire and quantum
dots- capable of high sensitivity and prototype model for the theoretical study of sensor working
mechanisms that are purposely realized are:
1D nanostrip of width lower than 100nm are deposited by means of reactive sputtering of compact
semiconducting oxides and the subsequent patterning with X-ray and electron lithography or subtractive
techniques like reactive ion etching and ion beam milling
Ultralong beltlike and nanowires (Nb) of MOX obtained by evaporating
metal oxide powders at high temperatures. The as-synthesized oxide
nanobelts are pure, structurally uniform, and single crystalline. The
beltlike morphology appears to be a distinctive and common structural
feature for the family of semiconducting oxides. The extraordinary
sensing properties of semiconducting nanobelts have been recently
shown. Free carriers should cross the belts bulk along the axis in a
pinched-off FET (Field Emission Transistor) channel-like way. The
presence of poisoning species should switch the structures from
pinched-off to conductive channel, strongly modifying the electrical
properties. The nanobelts (Nb) will be functionalised to improve
specificity towards target gaseous species. Au prepatterned substrates
can be employed to promote the catalytic growth of epitaxial metal
oxide films in the form of nanowires.
SEM and TEM micrographs of nanowires and nanobelts
Optical mesoscopic gas sensors
In the past few years, progress has been achieved in the synthesis, structural characterization and
physical properties investigation of nanostructures. Due to their peculiar characteristics and size effects,
these materials often show some novel physical properties that are different from those of the bulk, and
are of great interest both for fundamental studies and for potential nanodevice applications. These
23metal oxide nanoparticles (SnO2, ZnO, In2O3) have photoluminescence emission in the visible range. In
the literature much attention has been devoted to study the optical properties of ZnO nanostructures,
an high gap metal oxide semiconductor in which oxygen vacancies -as in tin oxide- are deemed
responsible of doping.
We showed that PL spectra of tin oxide nanobelts is reversible quenched by NO2. The response is highly
selective towards humidity and other polluting species like CO and NH3. Ionosorbed gaseous species
that create surface states can quench the material luminescence by destroying radiative recombination
paths. The results foresee the development of a new class of selective metal oxide gas sensors.
1.2.2.4 Electronic Nose
An array of sensors is the core of the Artificial
Olfactory System (AOS). An AOS -also called
"electronic nose" (EN)- is a monitoring
instrument that detects a wide range of organic
and inorganic molecules down to the parts-per-
billion level. Since gases and gas mixtures are
identified by the electrical response pattern of
the entire array, the EN has an unique ability to
monitor and identify a wide variety of
SACMI EOS 835 olfactory system
compounds. Beside the development of sensors,
an effective ENs requires: (a) the ability to obtain reproducible gas sampling, (b) a systematic and
through experimentation, (c) the development of flexible and user friendly instrumentation control, and
(d) sophisticated data analysis techniques.
A collaboration with a medium size company, SACMI (Imola - Bologna), started in 2001 to engineer and
commercialize the research findings coming out from the SENSOR Lab. In 2003 the first commercial EN,
the SACMI EOS 835 olfactory system, based on the Pico-2 EN from the Sensor Lab, was put on the
market.
In the last few years we extended the gas sampling possibilities with a programmable autosampler (as
used in gas chromatography) and an automated gas mixing station, similar to the ones used for sensor
characterization, for testing the sensors in advance towards some gases characteristic of the food
headspace. We developed new methods for instrument control (hardware and sampling system), data
acquisition, storage, visualization, and exploratory data analysis.
We developed new procedures for controlling the instrument and creating a database in order to obtain
greater flexibility in experiment design and ease of use even by non experts. A well structured database
containing all measurement parameters is a key necessity for thorough data analysis.
We developed a user-interface for exploratory data analysis giving the possibility of rapid assessment of
the acquired data. The interface has been developed in Matlab and comprises the calculation of
summary statistics and two dimensional projections for data visualization. This allows the testing of
different combinations of instrument parameters in order to optimize the measurement protocols for
every particular application.
Below we present two successful application of the Pico EN.
Study and preparation of an Artificial Olfactory System for environmental and food applications
The use of ENs for food quality analysis tasks is twofold. ENs are normally used to discriminate different
classes of similar odor-emitting products. On the other hand, ENs can also be used to predict sensorial
24descriptors of food quality as determined by a panel (often one generically speaks of correlating EN and
sensory data). The figure shows e.g. the EN’s predicted outputs vs the true outputs of Hedonic Index
(HI) given by human panel for a coffee blend. EN’s can therefore represent a valid help for routine food
analysis.
A major application of EN for environmental monitoring is malodors evaluation. The comparative
advantage in e.g. on site landfill site measurements is the big odor intensities at stake: sensitivity is
therefore less of an issue. The PCA plot below shows the clustering for odour samples taken in 4
different locations of landfill site. EN is then able to distinguish and predict the odour intensity which is
customarily given by dynamic olfactometry.
Learning from data
For a large part of modern applied science (dealing with the analysis of complex systems) either first
principles are unknown or the systems under study are too complex to be mathematically described. On
the other hand, with the growing use of computers and low-cost sensors for data collection, there is a
great amount of data being generated by such systems. In the absence of first-principle models, such
readily available data can be used to estimate useful relationships between a system's variables based
25solely on the prediction ability of the estimate. Examples include medical diagnosis, data mining,
financial forecasting, bioinformatics and sensor systems such as the electronic nose (EN).
The aim of the analysis of data generated from an array of sensors is to find a relationship between the
sensors outputs and the odor class or the components concentration. To achieve this, first some
characteristic features have to be extracted from the response curves of the various sensors and then
the functional relationship between the feature vectors and the classes (concentrations) has to be
derived (i.e. parameters defining the function have to be estimated). The first step is usually
application-specific, while the second one (the proper supervised learning step) makes use of general
purpose statistical methods.
The pattern recognition problem for electronic noses is particularly demanding, as large intra-class
variability compared to a small inter-class separation is encountered in real applications along with a
relatively small number of available measurements.
Presently, data analysis for EN is mainly based on principal component analysis and classical
chemometrics methods such as partial least squares and multilinear regression. Several non-parametric
methods have been tried out but not optimized. In the important case of multilayer perceptrons, for
example, complexity control relies on not well founded heuristics, feature reduction is not performed
systematically, and training algorithms are often confined to simple gradient descent techniques.
The Sensor Lab is pursuing systematic data analysis by
means of state-of-the-art machine learning techniques.
We design and test different feature selection methods
and complexity control strategies for both multilayer
perceptrons and statistical learning techniques like
Support Vector Machines, which have not been used so
far in the sensor field (2003).
As for feature selection, we compare different methods
acting on the standard preprocessed data. In this way it
is possible to judge the importance of each sensor for
the odour classification. Different sensors and different
sensor operational conditions are tested. Feature
selection can reduce not only the cost of recognition but
in some cases it can also provide a better classification accuracy due to finite sample size effects.
Supervised learning is tackled with properly designed neural networks (using early stopping and
regularization) and Support Vector Machines. Careful model order selection is necessary for obtaining
accurate and robust classifiers. Recently proposed learning machines, consisting in combinations or
ensambles of classifiers, like boosting, are also explored.
A research activity on pattern recognition for DNA microarray analysis has been recently started.
1.2.2.5 Introduction to theoretical research activity
A coherently driven exciton–biexciton transition may enable one to propagate a probe light beam within
the CuCl exciton-polariton stop-band where radiation is otherwise completely reflected. We find that he
stop-band transparency, favored by the narrow linewidth of the biexciton, can be easily controlled via
the frequency and intensity of the external pump beam. Such a control of the transparency is expected
to take place both in bulk and in microcavities semiconductors. Applications for monitoring exciton
molecules dephasings and for substantial ponderomotive effects associated with the probe pulse
26compression are under way.
We have exploited tunable Fano quantum interference to devise a novel all-optical switching scheme.
One of the advantages of all-optical devices over the opto-electronic ones is their inherent potential to
provide improved high-speed data processing. Our scheme is quite sensitive and accurate where full
control of the switch on-off position is accomplished by an external light beam that controls the degree
of quantum interference. We anticipate a significant on-off ratio over a broad bandwidth of the order of
0.1 THz with response and recovery both on sub-picosecond time scales which reveals the potential that
such a quantum interference based all-optical switch holds for optical communication.
1.2.2.6 Instrumentation
Two Magnetron Sputtering plants in a clean room
(Class 100) able to perform DC and RF sputtering
and equipped with loadlock systems to introduce
and extract the samples without breaking the
vacuum.
Three experimental set-up for the deposition of
unidimensional single crystalline nanostructures
(nanowires, nanobelts, nanocomb …) with the
vapor transport process equipped with tubular
furnaces capable to reach 1600°C, alumina tubes
connected with a vacuum pumping system and
mass-flow controllers for the regulation of carrier
gases.
Three furnaces for thermal oxidation in dry or
humid air and treatments in inert atmosphere.
Two microwelders for wire bonding and packaging
of sensors, one based on local welding and the
other a brand new Kulicke & Soffa Wedge Bonder
Four advanced systems for the measurement of
the DC and AC electrical response of up to 10
sensors to gas mixtures at variable humidity and
controlled temperature. Other features are: MS
Spectrometer to monitors the outlet of the test
chambers; Special module for ozone
characterization; Kelvin Probe measurement;
Photoactivated characterization.
27Electronic Nose with dynamic headspace sampling
and (optionally) a static headspace programmable
autosampler
An experimental set-up for optical characterisation
made by a gas chamber equipped with a quartz
window. On the bench a Multiline Ar Laser, a He-
Cd laser, a Quartz Tungsten Halogen Lamp, a
single monochromator and a CCD Camera can
detect the resistance phoactivated response, the
photoluminescence and reflectance spectra in the
1Ev-4Ev range. A Kelvin Probe head placed inside
the chamber measures the Surface Photo Voltage
High resolution field-emission Scanning electron
microscope for material characterization: SE –
BSE – STEM imaging, EDX compositional analysis
and mapping.
In situ nano-manipulators:
two independent positioners with low-current
measurement capability for
in-situ SEM manipulation and electrical
characterization of nanostructures.
An AFM operating in air at normal pressure with
six standard SPM modes: C-AFM, LFM, NC-AFM,
IC-AFM, Phase and STM.
A Glove Box allows obtaining local
spectroscopical measurements in air and in a
controlled atmosphere.
The system is equipped with dip pen and nano-
manipulation tools.
1.2.2.7 Publications 2005
An extract of 2005 publications on ISI Journals is reported below
1. C. Baratto, E. Comini G. Faglia , G. Sberveglieri , M. Zha, A. Zappettini “Metal oxide
nanocrystals for gas sensing” Sensors and Actuators B 109 (2005) 2–6.
2. C. Baratto, G. Faglia, M. Pardo, M. Vezzoli, L. Boarino, M. Maffei, S. Bossi, G. Sberveglieri,
”Monitoring Plants Health in Greenhouse For Space Missions”, Sensors and Actuators B, 108
(2005), 278-284.
3. A. Ponzoni, E. Comini, M. Ferroni, G. Sberveglieri, “Nanostructured WO3 deposited by modified
thermal evaporation for gas- sensing applications”, Thin Solid Films 490 (2005), 81-85.
284. D. Calestani, M. Zha, G. Salviati, L. Lazzarini, E. Comini, G. Sberveglieri, “Nucleation and
growth of SnO2 nanowires”, J. Crystal Growth 275 (2005) 2083-2087.
5. A Trinchi, W Wlodarski, Y X Li, G Faglia and G Sberveglieri, “Pt/Ga2O3/SiC MRISiC devices: a
study of the hydrogen response”, J. Phys. D: Appl. Phys. 38 (2005) 754–763.
6. P.G. Merli, V. Morandi, G. Savini, M. Ferroni and G. Sberveglieri, “Scanning Electron Microscopy
of dopant distribution in semiconductors”, Applied Physics Letters 86 (2005), Art. No. 101916.
7. V. Guidi, G. Martinelli, G. Schiffrer, A. Vomiero, C. Scian, G. Della Mea, E. Comini, M. Ferroni,
G. Sberveglieri, “Selective sublimation processing of thin films for gas sensing”, Sensors and
Actuators B 108 (2005) 15–20.
8. Candeloro P, Carpentiero A, Cabrini S, Di Fabrizio E, Comini E, Baratto C, Faglia G, Sberveglieri
G, Gerardino A, “SnO2 sub-micron wires for gas sensors”, MICROELECTRONIC ENGINEERING,
78-79, Sp. Iss. SI (2005) 178-184.
9. D. Calestani, M. Zha, A. Zappettini, L. Lazzarini, G. Salviati, L. Zanotti, G. Sberveglieri,
“Structural and optical study of SnO2 nanobelts and nanowires”, Mat. Sci. Eng. C, 2005 in
press.
10. Alessandri, I; Comini, E; Bontempi, E; Sberveglieri, G.; Depero, “Structural characterization of
V2O5-TiO2 thin films deposited by RF sputtering from a titanium target with vanadium insets”,
LE, SENSORS AND ACTUATORS B-CHEMICAL, 109, 1 (2005): 47-51.
11. M. Falasconi , M. Pardo, G. Sberveglieri, F. Battistutta, M. Piloni and R. Zironi, “Study of white
truffle aging with SPME-GC-MS and the Pico2-Electronic Nose”, Sensors and Actuators B, 106
(2005), 88-94.
12. M. Falasconi, M. Pardo, G. Sberveglieri, I. Riccò and A. Bresciani, “The novel EOS835 electronic
nose and data analysis for evaluating Coffee
ripening”, Sensors and Actuators B 110 (2005), 73-80.
13. Comini E, Faglia G, Sberveglieri G, Calestani D, Zanotti L, Zha M., “Tin oxide nanobelts
electrical and sensing properties”, SENSORS AND ACTUATORS B-CHEMICAL 111: Sp. Iss. SI
(2005), 2-6.
14. Morandi S, Ghiotti G, Chiorino A, Bonelli B, Comini E, Sberveglieri G, “MoO3-WO3 mixed oxide
powder and thin films for gas sensing devices: A spectroscopic characterization”, SENSORS
AND ACTUATORS B-CHEMICAL 111: Sp. Iss. SI (2005), 28-35.
15. Kandasamy S, Trinchi A, Wlodarski W, Comini E, Sberveglieri G, “Hydrogen and hydrocarbon
gas sensing performance of Pt/WO3/SiC MROSiC devices”, SENSORS AND ACTUATORS B-
CHEMICAL 111: Sp. Iss. SI, (2005), 111-116.
16. Sberveglieri G, “Nano-structured solid-state gas sensors with superior performance
(NANOS4)”, MATERIALS TECHNOLOGY 20, 1 (2005), 39-43.
17. G. Faglia, C. Baratto, G. Sberveglieri, M. Zha, A. Zappettini, “Adsorption effects of NO2 at ppm
level on visible photoluminescence response of SnO2 nanobelts”, Applied Physics Letters, 86
(2005), Art. No. 011923.
18. M. Pardo and G. Sberveglieri, “Classification of electronic nose data with Support Vector
Machines”, Sensors and Actuators B, 107 (2005), 730-737.
19. M. Pardo, B. C. Sisk, G. Sberveglieri, N. S. Lewis, “Comparison of Fisher’s Linear Discriminant
29and Multilayer Perceptron Networks for Classification of Chemical Vapor Detector Data from
Various Sources and Systems”, Sensors and Actuators B (accepted).
20. M. Pardo , L.G. Kwong, G. Sberveglieri, K. Brubaker, J. F. Schneider, W.R. Penrose, J.R.
Stetter, “Data Analysis for a Hybrid Sensor Array”, Sensors and Actuators B 106 (2005), 137-
144.
21. Comini E, Guidi V, Ferroni M, Sberveglieri G, “Detection of landfill gases by chemoresistive
sensors based on titanium, molybdenum, tungsten oxides”, IEEE SENSORS JOURNAL 5, 1
(2005), 4-11.
22. M. Falasconi , E. Gobbi, M. Pardo, M. della Torre, A. Bresciani, G. Sberveglieri, “Detection of
toxigenic strains of Fusarium verticillioides in corn by Electronic Olfactory System”, Sensors
and Actuators B, 108 (2005), 250-257.
23. V. Guidi, G. Martinelli, G. Schiffrer, A. Vomiero, G. Della Mea, E. Comini, M. Ferroni, and G.
Sberveglieri, “Diffusion-equation approach to describe ionic mobility in nanostructured titania”,
Physical Review B 72 (2005), Art. No. 155401.
24. E. Comini, M. Ferroni, V. Guidi, A. Vomiero,P.G. Merli, V. Morandi, M. Sacerdoti , G. Della Mea,
G. Sberveglieri, “Effects of Ta/Nb doping on titania-based thin films for gas-sensing”, Sensors
and Actuators B 108 (2005) 21–28.
25. Morandi S, Ghiotti G, Chiorino A, Comini E, “FT-IR and UV-Vis-NIR characterisation of pure and
mixed MoO3 and WO3 thin films”, THIN SOLID FILMS, 490, 1 (2005): 74-80.
26. Comini E, Yubao L, Brando Y, Sberveglieri G, “Gas sensing properties of MoO3 nanorods to CO
and CH3OH”, CHEMICAL PHYSICS LETTERS, 407, 4-6 (2005): 368-371.
27. A Trinchi, W Wlodarski, G Faglia, A Ponzoni, E Comini, G Sberveglieri, “High Temperature
Hydrocarbon Sensing with Pt-Thin Ga2O3-SiC Diodes”, Materials Science Forum, 483-485
(2005) 1033-1038.
28. M. Artoni, G.La Rocca and F. Bassani “Resonantly absorbing one-dimensional photonic
crystals” Phys. Rev. E 72, 046604 (2005)
29. Jin-Hui Wu, Jin-Yue Gao, Ji-Hua Xu, L. Silvestri, M. Artoni, G. C. La Rocca, and F. Bassani
“Ultrafast All Optical Switching via Tunable Fano Interference” Phys. Rev. Lett. 95, 057401
(2005).
30. S. Rebic, D. Vitali, C. Ottaviani, P. Tombesi, M. Artoni, F. Cataliotti, R.Corbalan “Quantum
theory of a polarization phase-gate in an atomic tripod configuration” Optics and Spectroscopy
99, 264 (2005)
31. S. Rebic, D.Vitali, C.Ottaviani, P. Tombesi, M.Artoni, F.Cataliotti, and R. Corbalan "A proposal
for an optical implementation of a universal quantum phase gate” International Journal of
Quantum Information, 3, 245 (2005).
32. D. Embriaco, M. L. Chiofalo, M. Artoni, and G. C. La Rocca “Effects of atomic interactions on the
resonant tunneling of sodium condensates” Journal of Optics B, Quantum Semiclass. 7, S59
(2005).
Book:
30"Electromagnetically Induced Transparency”
M. Artoni
Encyclopedia of Condensed Matter Physics, p. 36 Elsevier (2005).
311.2.3 SECTION OF MATERIALS SCIENCE AND TECHNOLOGY
The section of Materials Science and Technology is aimed at generating, developing, and promoting
knowledge on advanced and traditional materials, on the technologies related to their design and
production, and on their engineering applications.
The section is part of INSTM (“Italian National Consortium of Materials Science and Technology”)
Research Unit – Brescia and is also member of INSTM Reference Centre NIPLAB (“Laboratorio di
Nanocompositi e Ibridi Polimerici Multifunzionali”). The section develops research activity at
international level in the frame of:
• Network of Excellence (NOE) Nanofun-poly (European network for advanced research in polymer
based nanocomposites);
• European Structural Integrity Society (ESIS), Technical Committee 4 (Polymers, Adhesives and
Composites).
The main research areas are:
1. Development of advanced engineering polymeric materials
2. Mechanics of polymers, composites and nanocomposites
3. Rheology of polymers and polymer-based systems
4. Technology and engineering of plastics products
1.2.3.1 Development of advanced engineering polymeric materials
1.2.3.1.1 Model polymer-based nanocomposites
This research is aimed at studying structure-property relationships in model nanocomposites having a
simple structure (amorphous and uncrosslinked matrix, perfect exfoliation, etc.). The results should be
employed to interpret the behaviour of more complex systems (crosslinked matrix, semicrystalline
polymer matrix).
Model poly(butyl methacrylate) / organoclay systems are prepared by solution blending and their
structural characteristics are investigated by X-ray diffraction. The effect of the polymer-clay interface
chemistry and of the organoclay content on the mechanical behaviour of these materials is investigated
by dynamic mechanical thermal analysis and uniaxial tensile tests.
Uncrosslinked natural rubber / organoclays nanocomposites are also prepared by solution blending and
their mechanical behaviour is compared with that of systems of various degrees of crosslinking. The
level of intercalation/exfoliation of the clay within the material and elastomer/filler interactions are
investigated by X-ray diffraction, transmission electron microscopy, swelling and calorimetric
experiments. The results are compared with those obtained for rubber nanocomposites produced by
melt mixing according to industrial procedures.
Further, crosslinked nanocomposites based on epoxy resins are studied. In particular, epoxy / layered
silicates and epoxy / carbon nanotubes nanocomposites are prepared and subjected to structural and
mechanical characterization. The effect of nanofiller on the curing kinetics of the materials is also
investigated via differential scanning calorimetry. (Ref.: iC. 1).
Collaborations: NOE Nanofun-poly, Politecnico di Milano (I), University of Brescia (“Dipartimento di
Ingegneria Meccanica”) (I)
Financing: INSTM (Project PRISMA, 2002-2004)
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