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Thursday, 4 December 2014 Venue: Pacific Coffee, Ground Floor of
E2 (North Wing)
8 : 0 0 p m – 1 0 : 0 0 p m Welcome Gathering Free
Attendance
Friday, 5 December 2014 Venue: E4-G051, Anthony Lau Building-Tai
Fung Lecture Hall, Ground Floor
9 : 0 0 a m – 9 : 2 0 a m Opening Remarks (Associate Dean of
FST) Presentation of Souvenirs
Group Photo
Moderator Prof. Haydn H. D. CHEN
9 : 2 0 a m – 1 0 : 0 0 a m Keynote Speech Prof. Shangjr GWO
Session 1 Chair Prof. Chi-Tai Kwok
1 0 : 0 0 a m – 1 0 : 3 0 a m Synchrotron x-ray scattering study
of nano ferroelectric superlattice structure Dr. Hsin-Yi LEE
1 0 : 3 0 a m – 1 1 : 0 0 a m Coffee Break
1 1 : 0 0 a m - 1 1 : 3 0 a m Effect of Composition on the
Fracture Toughness of Ti1-xZrxN Hard Coatings Prof. Jia-Hong
HUANG
1 1 : 3 0 p m - 1 2 : 0 0 p m Energy Storage for Remote Area
Power Supply Systems Prof. Sammy Lap Ip CHAN
1 2 : 0 0 p m - 1 2 : 3 0 p m Electrical Field Dependence of
Electrocaloric Effect in Relaxor Ferroelectrics Prof. Sheng-Guo
LU
1 2 : 3 0 p m – 2 : 3 0 p m Lunch
Session 2 Chair Prof. Jia-Hong HUANG
2 : 3 0 p m – 3 : 0 0 p m Reduction-resistance enhancement of
CaMgSi2O6 glass-ceramics as microwave dielectrics
Prof. Chen-Chia CHOU
3 : 0 0 p m – 3 : 3 0 p m The study of the strain and
orientation on the dielectric properties of BaTiO3-based thin films
Prof. Jiwei ZHAI
3 : 3 0 p m – 4 : 0 0 p m Hot-stage transmission electron
microscopy study of (Na, K)NbO3 based lead-free piezoceramics
Dr. Shengbo LU
4 : 0 0 p m – 4 : 3 0 p m Coffee Break
4 : 3 0 p m – 5 : 0 0 p m Structural and electrical properties
of titanium oxynitride film on MgO (001) substrate
Prof. Li CHANG
5 : 0 0 p m – 5 : 3 0 p m Observations of New Precipitation
Phenomena in Duplex Stainless Steels Prof. Kin Ho LO
5 : 3 0 p m – 6 : 0 0 p m Overall Discussion Prof. Chi Tai KWOK
Prof. Jia-Hong HUANG
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Saturday, 6 December 2014 Venue: E4-G051, Anthony Lau
Building-Tai Fung Lecture Hall, Ground Floor
1 1 : 0 0 a m – 1 2 : 0 0 p m Campus Tour and Networking
1 2 : 0 0 p m – 2 : 0 0 p m Lunch
Session 3 Chair Prof. Igor RAEVSKII
2 : 0 0 p m – 2 : 3 0 p m The effect of the bias field on the
dielectric and pyroelectric response of Pb(Fe0.5Ta0.5)O3 relaxor
multiferroic ceramics
Dr. Victor TITOV
2 : 3 0 p m – 3 : 0 0 p m Electronic, Magnetic, and Catalytic
properties of 2D Metal Dichalcogenides
Dr. Hui PAN
3 : 0 0 p m – 3 : 3 0 p m Laser surface alloying of copper with
tungsten for corrosion and wear resistance Prof. Chi Tai KWOK
3 : 3 0 p m – 4 : 0 0 p m Coffee Break
4 : 0 0 p m – 4 : 3 0 p m Scanning thermoelectric microscopy of
local thermal conductivity and Seebeck coefficient of
thermoelectric materials
Prof. Huarong ZENG
4 : 3 0 p m – 5 : 0 0 p m Oxide Magnetic Nanostructures
Investigated by X-ray Absorption Spectroscopy Prof. Yuan-Chieh
TSENG
6 : 3 0 p m – 8 : 0 0 p m Banquet Fortune Inn, UM
Sunday, 7 December 2014 Venue: E4-G051, Anthony Lau Building-Tai
Fung Lecture Hall, Ground Floor
Session 4
Chair Prof. Sammy Lap Ip CHAN
9 : 0 0 a m – 9 : 3 0 a m Studies of ferroelectric and magnetic
phase transitions in multiferroic PbFe0.5Nb0.5O3 –PbZrO3 solid
solutions
Prof. Igor RAEVSKII
9 : 3 0 a m – 1 0 : 0 0 a m Enhanced electrical conductivity of
ZnSnO amorphous nanocomposite Dr. Ling LEE
1 0 : 0 0 a m – 1 0 : 3 0 a m X-ray Residual Stress Measurement
on TiN thin Films using Average X-ray Strain (AXS) Method
Ms An-ni WANG
1 0 : 3 0 a m – 1 1 : 0 0 a m Coffee Break
1 1 : 0 0 a m – 1 1 : 4 5 a m Final discussion Sessions
Chairs
1 1 : 4 5 a m – 1 2 : 0 0 p m Closing Remarks Prof. Haydn H. D.
CHEN
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Speakers with Affiliation
Seq Name Affiliation
1 Prof. Haydn H. D. CHEN Institute of Applied Physics and
Materials Engineering, Faculty of Science and Technology,
University of Macau, Macau SAR
2 Prof. Shangjr GWO Department of Physics, National Tsing Hua
University, Taiwan National Synchrotron Radiation Research Center,
Taiwan
3 Dr. Hsin-Yi LEE National Synchrotron Radiation Research
Center, Taiwan
4 Prof. Jia-Hong HUANG Department of Engineering and System
Science, National Tsing Hua University, Taiwan
5 Prof. Sammy Lap Ip CHAN School of Materials Science &
Engineering, University of New South Wales, Australia
6 Prof. Sheng-Guo LU School of Materials and Energy, Guangdong
University of Technology, China
7 Prof. Chen-Chia CHOU Department of Mechanical Engineering,
National Taiwan University of Science and Technology, Taiwan
8 Prof. Jiwei ZHAI Functional Materials Research Laboratory,
Tongji University, China
9 Dr. Shengbo LU Jawbone Ltd, China
10 Prof. Li CHANG Department of Materials Science and
Engineering , National Chiao Tung University, Taiwan
11 Prof. Kin Ho LO Department of Electromechanical Engineering,
Faculty of Science and Technology, University of Macau, Macau SAR
Institute of Applied Physics and Materials Engineering, Faculty of
Science and Technology, University of Macau, Macau SAR
12 Dr. Victor TITOV Research Institute of Physics and Physics
Department, Southern Federal University, Russia
13 Dr. Hui PAN Institute of Applied Physics and Materials
Engineering, Faculty of Science and Technology, University of
Macau, Macau SAR
14 Prof. Chi Tat KWOK Department of Electromechanical
Engineering, Faculty of Science and Technology, University of
Macau, Macau SAR Institute of Applied Physics and Materials
Engineering, Faculty of Science and Technology, University of
Macau, Macau SAR
15 Prof. Huarong ZENG Key Laboratory of Inorganic Functional
Materials and Devices, Shanghai Institute of Ceramics, Chinese
Academy of Sciences, China
16 Prof. Yuan-Chieh TSENG Department of Materials Science and
Engineering , National Chiao Tung University, Taiwan
17 Prof. Igor RAEVSKII Research Institute of Physics and Physics
Department, Southern Federal University, Russia
18 Dr. Ling LEE Center of Nanoscience and Technology, Tunghai
University, Taiwan Department of Chemical and Materials
Engineering, Tunghai University, Taiwan
19 Ms. An-Ni WANG Department of Engineering and System Science,
National Tsing Hua University, Taiwan
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International Workshop on Functional Materials Organized by
Institute of Applied Physics and Materials Engineering (IAPME),
Faculty of Science and Technology, University of Macau, Macau
SAR
Keynote Speech – by Prof. Shangjr GWO Friday, 5 December 2014
Venue: E4-G051, Anthony Lau Building- Tai Fung Lecture Hall, Ground
Floor
Speaker Prof. Shangjr GWO
Plasmonic Metamaterials and Nanolasers for Nanophotonics
Shangjr GWO
Department of Physics, National Tsing-Hua University, Hsinchu
30013, Taiwan National Synchrotron Radiation Research Center,
Hsinchu 30076, Taiwan
Abstract Optical diffraction limits the spatial resolution of
light focusing and guiding by lenses, fibers, and waveguides to
about half of the light wavelength. In the past, this fundamental
limitation is an insurmountable barrier for optical imaging,
lithography, data storage, and optical integrated systems. Recent
advances based on the excitation of plasmons in metal
nanostructures by light (nanoplasmonics) have been demonstrated to
be able to overcome the diffraction barrier. In this talk, I will
present new developments in nanoplasmonics, including plasmonic
metamaterials and nanolasers. By using novel metal nanoparticle
films and metal–oxide–semiconductor nanostructures, we have
realized highly uniform and ultrasensitive surface enhanced Raman
spectroscopy (SERS) substrates, as well as ultralow-threshold,
all-color plasmonic nanolasers. These developments represent
significant progress toward realization of diffraction-unlimited
nanophotonics, which can offer unparalleled opportunities in
nanoscience and nanotechnology.
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Session 1 – Chaired by Prof. Chi-Tai KWOK
Friday, 5 December 2014 Venue: E4-G051, Anthony Lau Building-
Tai Fung Lecture Hall, Ground Floor
1.1 Speaker Dr. Hsin-Yi LEE
Synchrotron x-ray scattering study of nano ferroelectric
superlattice structure
Hsin-Yi LEE
National Synchrotron Radiation Research Center, 101 Hsin-Ann
Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
Abstract High quality of BaTiO3/LaNiO3 (BTO/LNO) and
(Ba0.48Sr0.52)TiO3/LaNiO3 (BST/LNO) superlattices was grown on an
Nb-doped SrTiO3 (STO) substrate by a triple-gun rf magnetron
sputtering system and computer control of the shutter opening; we
thereby controlled precisely the duration of deposition of each
layer of a superlattice. Synchrotron X-ray reflectivity and
high-resolution diffraction measurements were employed to
characterize the microstructure of these films. The formation of a
superlattice structure was confirmed through both the appearance of
Bragg peaks separated by Kiessig fringes in x-ray reflectivity
curves and the satellite peaks of a (002) diffraction pattern and
the secondary-ion mass spectrometry (SIMS) profile. The appearance
of discernible satellite peaks beside the main peak of the crystal
truncation rod observed for deposited films clearly demonstrates
that a well-defined superlattices structure is achievable through
rf sputtering growth. These BTO/LNO or BST/LNO superlattices films
reveal a partial strain relaxation and not fully strained state for
all modulation length even though the thickness of individual BTO
or BST and LNO layers is less than the critical thickness. The
dielectric properties of BTO/LNO and BST/LNO superlattices show a
significant enhancement with respect to the BTO or BST single layer
with the same thickness. From a macroscopic point of view, the
strain in the superlattice structure contributes significantly to
the dielectric enhancement. The evolution of surface and interface
roughness during heteroepitaxial growth of strained BaTiO3/LaNiO3
superlattices on SrTiO3 substrates was investigated using real-time
x-ray scattering measurements with synchrotron radiation under
in-situ rf sputtering. In these real-time experiments, the
roughness scaling of the growth front and interface of
superlattices with modulation length below and beyond the critical
thickness was studied against the bilayer number. Our results
provide the first evidence for power-law scaling of the
root-mean-square roughness of interface and surface in the
superlattice structure.
1.2 Speaker Prof. Jia-Hong HUANG
Effect of Composition on the Fracture Toughness of Ti1-xZrxN
Hard Coatings
Jia-Hong HUANG, You-Fu CHEN and Ge-Ping YU
Department of Engineering and System Science, National Tsing Hua
University, Taiwan
Abstract The objectives of this study were to measure the
fracture toughness of Ti1-xZrxN hard coatings using the internal
energy induced cracking (IEIC) method and investigate the
compositional effect on the fracture toughness, from which the
optimum composition for fracture toughness could be attained.
Ti1-xZrxN was selected to be the model system, because Ti1-xZrxN
remained
single phase structure in the entire compositional range at a
deposition temperature below 500C. Three compositions of Ti1-xZrxN
coatings, x = 0.25, 0.55 and 0.85, were deposited by unbalanced
magnetron sputtering. The IEIC method involved the residual stress
measured by the laser curvature method, Young’s modulus obtained
from nanoindentation and the film thickness from SEM
cross-sectional image. The residual stress and film thickness
before specimen fracture were used to calculate the elastic stored
energy (Gs), from which the fracture toughness could be derived.
The resultant fracture toughness of the Ti1-xZrxN coatings varied
with Zr fraction, ranging from 26.0 to 48.7 J/m
2, and reaching a maximum for Ti0.15Zr0.85N. The results
showed
that adding Zr atoms into TiN could effectively increase the
fracture toughness. The atomic size difference of Zr and Ti may
play an important role on increase of fracture toughness. The
increase of fracture toughness for Ti0.15Zr0.85N was higher than
that for Ti0.75Zr0.25N. This asymmetrical behavior could be
attributed to the difference in lattice constants between Ti-rich
and Zr-rich compounds, in which the capability of increasing
elastic stored energy may be higher for a smaller Ti atom
incorporated into a larger Zr site in ZrN lattice. It is also found
that IEIC method can be applied as long as the cracking occurs
inside the film. If the cracks penetrate into the substrate, the
contribution of substrate cracking should be considered.
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1.3 Speaker Prof. Sammy Lap Ip CHAN
Energy Storage for Remote Area Power Supply Systems
Sammy Lap Ip CHAN
School of Materials Science & Engineering, University of New
South Wales, Australia
Abstract One of the possible solutions to provide electricity to
a remote area community is to build a self-sustaining power
generation system by harvesting the renewable energy. However, the
intermittent nature of renewable energy has become a key issue to
be solved in order to guarantee a non-interruptible power supply at
all times. This presentation discusses the requirements for such an
energy storage system to be used in remote area power supply
(RAPS), and highlights batteries and hydrogen-fuel cells system as
the most promising and flexible options. The benefits and
limitations of present and potential battery systems will be
explored. Another solution is to generate hydrogen in an
electrolyser using excess photovoltaic input in the RAPS, and to
store it as metal hydride for later use when insufficient direct
solar electricity is available. For numerous reasons, particularly
the absence of self-discharge, reliability, longevity and safety in
transport and operation, we advocate serious consideration of RAPS
using this metal-hydride storage of hydrogen. Technical issues
surrounding the use of hydrogen storage, as well as the choices of
metal storage alloys, will also be included in the
presentation.
1.4 Speaker Prof. Sheng-Guo LU
Electrical Field Dependence of Electrocaloric Effect in Relaxor
Ferroelectrics
S. G. LU1, Z. H. Cai
1, Y. X. OUYANG
1, Y. M. DENG
1 and Q. M. ZHANG
2
1School of Materials and Energy, Guangdong University of
Technology, Guangzhou, 510006, China
2Department of Electrical Engineering and Materials Research
Institute, The Pennsylvania State University, University Park,
PA
16802, USA Abstract Relaxor ferroelectrics demonstrate great
potential in achieving large electrocaloric effect (ECE) which
could be used as cooling devices in microelectronics industry as
well as in daily life. The electrical field dependence of ECE,
however, remains unclear, especially for relaxor ferroelectrics.
The electrical field dependence of ECE can help predict the ECE
characteristics of cooling devices, facilitating the design of high
efficient refrigerators. In this work, relaxor ferroelectric
0.71Pb(Mg1/3Nb2/3)O3 - 0.29PbTiO3 (PMN-PT) single crystals,
(PbLa)(ZrTi)O3 ceramic thin films, and poly(vinylidene fluoride –
trifluoroethylene – chlorofluoroethylene) (P(VDF-TrFE-CFE))
/poly(vinylidene fluoride – trifluoroethylene) (P(VDF-TrFE))
terpolymer/copolymer blends were used to investigate the electrical
field dependence of ECE. Direct method was used to measure the ECE
adiabatic temperature change as a function of electrical field.
Results indicate that, the ECE temperature change tends to show
quadratic
relationship, i.e., T ~ E2, at lower electrical fields. At
higher fields, the temperature change has a tendency towards
saturation in
terms of the relationship, i.e., T ~ E2/3
. In the mediate electrical fields, the temperature change shows
linear relationship with electrical field. The above phenomena
could be illustrated in the frame of approximately continuous phase
transition derived Belov-Goryaga equation, which can be modified
for ferroelectrics.
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Session 2 – Chaired by Prof. Jia-Hong HUANG
Friday, 5 December 2014 Venue: E4-G051, Anthony Lau Building-
Tai Fung Lecture Hall, Ground Floor
2.1 Speaker Prof. Chen-Chia CHOU
Reduction-resistance enhancement of CaMgSi2O6 glass-ceramics as
microwave dielectrics
Chen Chia CHOU1, Kuei Chih FENG
1, 2, Li Wen CHU
3,
Igor P. RAEVSKIY4, Haydn CHEN
5
1Department of Mechanical Engineering, National Taiwan
University of Science and Technology, Taipei 106, Taiwan, ROC.
2Prosperity Dielectrics Corporation, Taoyuan 338, Taiwan,
R.O.C.
3Walsin Technology Corporation, Kaohsiung 806, Taiwan,
R.O.C.
4 Physics Department, Southern Federal University, Rostov on
Don, Russia 5Faculty of Science and Technology, University of
Macau, Macau, China.
Abstract Design of a highly reduction-resistant CaMgSi2O6
glass-ceramics system as sintered in reducing atmosphere and
applicable to microwave dielectric material was investigated in
this study. The reduction-resistant mechanism, charge transitions
and microwave dielectric properties were analyzed using X-ray
photoelectron spectroscopy (XPS) and electrical property
measurements. Experimental results show that diopside glass-ceramic
sintered at reducing atmosphere reveals low resistivities and low
quality factors due to formation of electrons and oxygen vacancies
in the lattice. After doped with amphoteric ion of Al2O3 in the
CaMgSi2O6 glass-ceramic, it shows that the increased resistances
are attributed to Al
3+ occupancy of silicon site to
act as an acceptor, which induces the oxygen vacancies to
compensate the electron. Moreover, the Al3+
may also occupy the magnesium site acting as the donor to reduce
the oxygen vacancies, and consequently increases quality factors of
materials. The highly reduction-resistant diopside glass-ceramic
forming donor-acceptor complexes can be employed in
base-metal-electroded (BME) MLCC devices.
2.2 Speaker Prof. Jiwei ZHAI
The study of the strain and orientation on the dielectric
properties of BaTiO3-based thin films
Jiwei ZHAI
Functional Materials Research Laboratory, Tongji University,
Shanghai 200092, China Abstract Ferroelectric and dielectric
materials in their bulk ceramics or thin film forms offer a wide
range of applications. New and enhanced properties can result from
different microstructure configurations using these complex oxides
ferroelectric and dielectric thin films. In this presentation I
shall describe some of our current works in the following areas
with illustrative examples, suggested physical mechanisms and its
microwave properties: (1) The effects of orientation on the
microstructure and dielectric properties of Barium stannate
titanate (BaSnxTi1-xO3, BTS) thin films were investigated. BTS thin
films with (100), (110) and (111) orientation were also grown on
LNO buffer (100), (110) and (111) LAO substrates through sol-gel
process, respectively. The in-plane and out-of-plane dielectric
properties of the films were measured on interdigital capacitor and
paralle plate capacitor structure, respectively. A strong
correlation was obtained between the dielectric properties and the
orientation of BTS thin films. The results showed the dependences
of dielectric constant and tunability on orientation were existed,
irrespective of the strain and electrode capacitor geometry. (2)
The effects of strain on the dielectric properties of BTS thin
films were investigated. The magnitude of the strain of films was
controlled by using substrates with different thermal expansion
coefficients and lattice constant. The dielectric properties of BTS
thin films were characterized as a function of the film strain and
the influence of film strain on the tunability had been discussed.
(3) The in-plane dielectric and microwave properties of BTS thin
films grown on (100) LAO single-crystal substrates through sol-gel
process were investigated. The tunability of BTS films grown on LAO
substrate at 1, 5 and 10 GHz was 17.5%, 16.1% and 15.8%,
respectively, measured at an applied voltage of 40 V.
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2.3 Speaker Dr. Shengbo LU
Hot-stage transmission electron microscopy study of (Na, K)NbO3
based lead-free piezoceramics
Shengbo Lu1 and Zhengkui Xu
2
1Jawbone Ltd., Shenzhen, P.R. of China
2Department of Physics and Materials Science, City University of
Hong Kong, Hong Kong
Abstract Hierarchical nanodomains assembled into micron-sized
stripe domains, which is believed to be associated with outstanding
piezoelectric properties, were observed at room temperature in a
typical lead free piezoceramics,
(Na0.52K0.48-x)(Nb0.95-xTa0.05)-xLiSbO3, with finely tuned
polymorphic phase boundaries (x=0.0465) by transmission electron
microscopy (TEM). The evolution of domain morphology and crystal
structure under heating and cooling cycles in the ceramics was
investigated by in-situ hot stage study. It is found that the
nanodomains are irreversibly transformed into micron-sized
rectangular domains during heating and cooling cycles, which lead
to the thermal instability of piezoelectric properties of the
materials. The in-situ hot stage study of nano-domain evolution in
Ba(Zr0.2Ti0.8)O3-50(Ba0.7Ca0.3)TiO3 piezoceramics is also presented
for a comparison purpose.
2.4 Speaker Prof. Li CHANG
Structural and electrical properties of titanium oxynitride film
on MgO (001) substrate
Li CHANG, Hien DO, Lin‐Lung WEI
Department of Materials Science and Engineering, National Chiao
Tung University, Hsinchu, Taiwan, 30010
Abstract TiN has versatile properties including high hardness,
chemical inertness, good conductivity, high melting point, and
anti‐reflection. Though it has received intensive studies for many
years, properties of the related TiNxOy films with the same NaCl
structure are far from basic understanding due to the fact that
single crystals are hardly available in reasonable size. We have
used pulsed laser deposition to grow high‐quality epitaxial TiNxOy
films on MgO substrate. The films have been characterized with
X‐ray photoelectron spectroscopy, x‐ray diffraction, Hall
measurement, nanoindentation, and atomic‐resolution scanning
transmission electron microscopy for the boding characteristics,
conductivity, mechanical properties, and interfacial structure. The
results show that titanium oxynitride TiNxOy films with different
chemical composition (0.63 ≤ x ≤ 1.11, 0.1 ≤ y ≤ 0.55) can be
heteroepitaxially grown on MgO (001) substrates at substrate
temperature of 700C. The TiNxOy films have good crystallinity *FWHM
of (002) X‐ray rocking curve ~ 58 ‐ 62 arcsec] even though they are
under fully compressive strain. The deposited TiNxOy films are
electrically conducting with resistivity of 28‐53 μΩ∙cm which
increases with oxygen content. The determined hardness H and
Young’s modulus E of about H ~ 17 ‐ 26 GPa and E ~ 355 ‐ 430 GPa,
both of which are found to decrease with increasing oxygen content
and decreasing nitrogen content. A spinel‐like phase of TiMgO has
been found at the TiNO/MgO interface with full coherency.
2.5 Speaker Prof. Kin Ho LO
Observations of New Precipitation Phenomena in Duplex Stainless
Steels
Kin Ho LO
Department of Electromechanical Engineering Institute of Applied
Physics and Materials Engineering
University of Macau, Macau, China
Abstract Ferritic-austenitic duplex stainless steels (DSSs) are
not new materials and so their precipitation behaviours have been
studied very extensively. In the literature, the austenite phase is
almost always considered ‘inert’, whereas the ferrite ‘active’,
when it comes to phase transformation and precipitation. However,
in this talk, it will be shown that over a narrow temperature range
and with prior plastic deformation, the austenite and the ferrite
will switch their roles as regards precipitation behaviour.
Furthermore, the discovery of an interesting domain structure in a
commercial DSS will be presented in this talk also.
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Session 3 – Chaired by Prof. Igor RAEVSKII Saturday, 6 December,
2014 Venue: E4-G051, Anthony Lau Building- Tai Fung Lecture Hall,
Ground Floor
3.1 Speaker Dr. Victor TITOV
The effect of the bias field on the dielectric and pyroelectric
response of Pb(Fe0.5Ta0.5)O3 relaxor multiferroic ceramics V.V.
Titov
1, S.I. Raevskaya
1, A.G. Lutokhin
1, I.P. Raevski
1, V.Yu. Shonov
1, Yu. N. Zakharov
1, A.V. Blazhevich
1, H. Chen
2, C.-C. Chou
3,
M.A.Malitskaya1
1 Research Institute of Physics and Physics Department, Southern
Federal University, 344090, Rostov on Don, Russia
2 Faculty of Science and Technology, University of Macau, Macau,
China
3 National Taiwan University of Science and Technology, 106,
Taipei,Taiwan
Abstract Recently we revealed a critical nature of the giant
field-induced pyroelectric response in single crystal
(1–x)Pb(Mg1/3Nb2/3)O3 – xPbTiO3 (PMN-xPT) with x=0.2, possessing
relaxor properties. In the present work we study the effect of the
bias field on the dielectric and pyroelectric responses of
PbFe0.5Ta0.5O3 (PFT) relaxor multiferroic ceramics.
Highly-resistive Li-doped PFT ceramics used for these studies
exhibits a very large dielectric response (maximum permittivity
values more than 20000 at 1 kHz) and a pronounced relaxor behavior.
Similar to PMN-PT relaxors permittivity ε maximum temperature Tmε
depends on the bias field strength E only above some threshold E
value. The dynamic pyroelectric coefficient maximum increases up to
the field corresponding to the critical point in the E-T phase
diagram (it can be roughly estimated from the inflexion in the
Tmε(E) dependence) and saturates at higher fields. It was found out
that PFT combines the properties of both relaxors and usual
ferroelectrics. The results obtained show that the origin of the
relaxor-like behavior in PbFe0.5Ta0.5O3 seems to be somewhat
different as compared to canonical relaxors. One of the possible
explanations is the coexistence of tetragonal and cubic phases in a
wide temperature range.
3.2 Speaker Dr. Hui PAN
Electronic, Magnetic, and Catalytic properties of 2D Metal
Dichalcogenides
PAN Hui
Institute of Applied Physics and Materials Engineering,
University of Macau, Macau, China Abstract Two-dimensional (2D)
transition metal dichalcogenides monolayers have attracted
increasing attention because of their unusual physical and chemical
properties. Here, a systematical study on the effects of
hydrogenation and strain on the physical and chemical properties of
2D MX2 (M=Mo, Nb, Ta, and V; X=S, Se, and Xe) monolayers is
presented. First, we find, by combining hydrogenation with external
tension, that magnetic properties of MoS2 monolayer can be tuned
from non-magnetism, to ferromagnetism, and further to non-magnetism
with the increase of tension. Secondly, we show that semi-metallic
and ferromagnetic VX2 monolayers can be tuned to be
nonmagnetic/anti-ferromagnetic and intrinsically semiconducting by
functionalizing with hydrogen atoms on one of their surfaces, and
ferromagnetic/anti-ferromagnetic and n-type semiconducting when
both of their two surfaces are fully covered by hydrogen atoms. The
ferromagnetism and anti-ferromagnetism are contributed to
carrier-mediated double-exchange and super-exchange, respectively.
Ferromagnetism is obtained in semi-metallic or lightly doped
semiconducting monolayers due to double-exchange of localized spins
with static localized states, while anti-ferromagnetism can be
achieved in intrinsic or heavily-doped semiconducting monolayer duo
to the super-exchange interaction. Finally, we systematically
investigate the hydrogen evolution reduction of metal
dichalcogenides monolayers. We find that metal disulfide monolayers
show better catalytic performance on hydrogen production than other
metal dichalcogenides. We show that their hydrogen evolution
reduction strongly depends on the hydrogen coverage and the
catalytic performance reduces with the increment of coverage
because of hydrogenation-induced lower conductivity. We further
show that the catalytic performance of vanadium disulfide monolayer
is comparable to that of Pt at lower hydrogen coverage and the
performance at higher coverage can be improved by hybridizing with
conducting nanomaterials to enhance conductivity. These metal
dichalcogenides monolayers may apply to mechanical valve, sensor,
spintronics, and water electrolysis for hydrogen production.
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3.3 Speaker Prof. Chi-Tai KWOK
Laser surface alloying of copper with tungsten for corrosion and
wear resistance
C.T. Kwok
Department of Electromechanical Engineering Institute of Applied
Physics and Materials Engineering
University of Macau, Macau, China Abstract Copper (Cu) is an
excellent electric contact material due to its high electrical and
thermal conductivities, high ductility, ease of fabrication and
reasonable affordability. However, its major drawbacks are low
hardness and low wear resistance. For many engineering
applications, the service lifetime of the components depends on
their surface properties, such as hardness, wear and corrosion
resistance. It is effective to fabricate a wear and corrosion
resistant surface layer on Cu while retaining the bulk properties
and structure of Cu. In order to enhance the corrosion and
electrical sliding wear resistance and hence the lifespan of Cu,
surface modification employing Tungsten (W) on Cu was attempted
using laser surface alloying with a 2.3-kW CW high power diode
laser. The microstructure, phase present and hardness of the
laser-alloyed copper with W were analyzed by SEM, XRD and
microhardness testing. Corrosion in 3.5 wt% NaCl solution and
artificial acid rain, dry wear in air, and wet wear in distilled
water and artificial acid rain were investigated and also compared
with Cu. The laser-alloyed specimens show significant improvement
in both corrosion resistance and wear resistance.
3.4 Speaker Prof. Huarong ZENG
Scanning thermoelectric microscopy of local thermal conductivity
and Seebeck coefficient of thermoelectric materials
H. R. Zeng, K. Q. Xu, G. R. Li, L. D. Chen
Shanghai Institute of Ceramics, Chinese Academy of Sciences 1295
Dingxi Road, Shanghai 200050, China
Abstract Nanostrucutres thermoelectric materials have become
Strong candidates for TE energy conversion due to their size effect
and energy filtering effect. For nanostructured TE material, it is
very important to measure local TE properties for understanding
local transport phenomena. But so far, it is still a very
challenging topic. Here a novel scanning thermoelectric microscopy
was developed based on the commercial atomic force microscope, its
working principle and its application to in-situ excite and measure
local thermoelectric properties will be described in details. This
new probe technique shows a promising tool for characterizing local
thermoelectric properties of nanoscale thermoelectric
materials.
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3.5 Speaker Prof. Yuan-Chieh TSENG
Oxide Magnetic Nanostructures Investigated by X-ray Absorption
Spectroscopy
Yuan-Chieh Tseng
Dept. of Materials Science & Engineering, National Chiao
Tung University 1001 Ta Hsueh Road, Hsin-Chu, Taiwan 30010
Abstract In this talk, the research advantage of
synchrotron-based x-ray absorption spectroscopy (XAS) in the field
of oxide magnetic nanostructures will be demonstrated with two
examples. In first example, a study focusing on the local symmetry
of Cu-dopant and resultant structural imperfections in mediating
Zn1-xCuxO nanoaprticles’ ferromagnetism (FM) will be reported. In
such nanostructure Cu appeared to preferably populate on the basal
plane of ZnO with a local symmetry of [CuO4]. This unique symmetry
was antiferromagnetic in nature, while electronically and
structurally coupled to surrounded oxygen vacancies (Vo) that
yielded a localized FM, because of a strong dependency on the
number/location of the [CuO4] symmetry. In surprise, the FM of
undoped but oxygen-deficient ZnO appeared to be more itinerant and
long-range, where Vo percolated the FM effectively and
isotropically through oxygen’s delocalized orbital, as validated by
several XAS techniques. By adopting the approach of structural
imperfection, this study clearly identifies Vo’s (defect’s) true
characters in mediating the FM of magnetic semiconductors which has
been thought of as a long standing debate. In second example, a
study of the characterizations for epitaxial-discrete and
single-oriented, sandwiched Fe3O4/CoxFe3-xO4/CoO magnetic
nanostructures on SrTiO3 will be shared. This nanostructure was
originally prepared as a Fe3O4-CoO core-shell structure using a
pulse laser deposition facility. However, because of the specific
(111) structural connection of the two oxide terminals, an
intermediate CoxFe3-xO4 phase naturally emerged to function as a
structural/electronic transition from CoO core to Fe3O4 shell at
atomic scale, laterally developing a
ferromagnetic(Fe3O4)/ferrimagnetic(CoxFe3-xO4)/antiferromagnetic(CoO)
tri-layer architecture. This was examined by the combination of XAS
and electron microscopy. Uncompensated spins (UCS) were observed at
the CoxFe3-xO4/CoO (111) interface as a result of the vigorous
ferromagnetic-antiferromagnetic interactions, which was responsible
for notable exchange bias and exchange enhancement. The UCS enabled
a strong locking effect at the CoxFe3-xO4/CoO interface, which
decoupled the CoxFe3-xO4/CoO magnetization reversal from softer
Fe3O4 because of a rather weak
ferromagnetic(Fe3O4)/ferromagnetic(CoxFe3-xO4) coupling, as
interpreted by switching-field-distribution (SFD) analyses. A
precise control of the phase decomposition condition can fine tune
the Fe3O4/CoO ratio, and magnetically modify CoxFe3-xO4 and UCS
behaviors accordingly, therefore serving as an effective means to
manipulate the nanostructure’s magnetic crystalline anisotropy and
coercivity strength.
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Session 4 – Chaired by Prof. Sammy Lap Ip CHAN
Sunday, 7 December, 2014 Venue: E4-G051, Anthony Lau Building-
Tai Fung Lecture Hall, Ground Floor
4.1 Speaker Prof. Igor RAEVSKII
Studies of ferroelectric and magnetic phase transitions in
multiferroic PbFe0.5Nb0.5O3 –PbZrO3 solid solutions
I.P. Raevski1, V.V. Laguta
2, M. Marysko
2, S.P. Kubrin
1, A.V. Blazhevich
1, H. Chen
3, C.-C. Chou
4, E.I. Sitalo
1, S. I.Raevskaya
1, V.V.
Titov1, D.A. Sarychev
1, M.A.Malitskaya
1, I.N. Zakharchenko
1
1 Research Institute of Physics and Physics Department, Southern
Federal University, 344090, Rostov on Don, Russia
2 Institute of Physics, AS CR, 18221 Prague, Czech Republic
3 Faculty of Science and Technology University of Macau, Macau,
China
4 National Taiwan University of Science and Technology, 106,
Taipei,Taiwan
Some peculiar features of magnetic x,T-phase diagram of the
(1-x)PbFe1/2Nb1/2O3-xPbTiO3 system at x≈0.1 have been ascribed
previously to the change of the lattice symmetry from rhombohedral
to tetragonal and/or to the decrease of the lattice parameter with
x. We carried out structural, dielectric, magnetization and
Mossbauer studies of the (1-x)PbFe1/2Nb1/2O3-xPbZrO3 system where
the symmetry remains rhombohedral while the lattice parameter
increases with x. However the magnetic x,T-phase diagram of
(1-x)PbFe1/2Nb1/2O3-xPbZrO3 appeared to be very similar to that of
(1-x)PbFe1/2Nb1/2O3-xPbTiO3. Anomalies of composition dependence of
magnetic phase transition temperatures at x≈0.1 are supposed to be
due to the percolation phase transition.
4.2 Speaker Dr. Ling LEE
Enhanced electrical conductivity of ZnSnO amorphous
nanocomposite
Ling Lee1,2
Chu-Shou Yang3, Ching-Shun Ku
4, and Hsin-Yi Lee
4
1Center of Nanoscience and Technology, Tunghai University,
Taiwan, Republic of China
2Department of Chemical and Materials Engineering, Tunghai
University, Taiwan, Republic of China 3Graduated Institute of
Electro-Optical Engineering, Tatung University, Taiwan, Republic of
China
4National Synchrotron Radiation Research Center, Taiwan,
Republic of China
Abstract In this talk, we would demonstrate the significantly
improved electrical conductivity of zinc tin oxide (ZnSnO) with a
particular structure of amorphous nanocomposite. The self-assembled
nanocomposite were prepared by molecular beam epitaxy on sapphire.
In-house and synchrotron radiation experiments showed that once the
tin composition ranges between 37 and 64 cation %, an amorphous
composite occurs with nanometer-scaled ZnO phases embedded in a
SnO2 matrix. High density of impurity bands distributed at the
interface of ZnO/SnO2 was attributed to the origin of the electron
transportation channel. In comparison to binary zinc oxide and tin
dioxide, a room temperature resistivity of 4.9×10
-4 Ω-cm is achieved, together with a
transmittance of larger than 95 % and 52 % in the visible range
and at 350 nm, and a flat surface with roughness less than 0.5 nm.
These results provide that the amorphous ZnSnO nanocomposite
exhibits feasibilities as an alternative candidate for indium-free
transparent conducting oxide.
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4.3 Speaker Ms. An-ni WANG
X-ray Residual Stress Measurement on TiN thin Films using
Average X-ray Strain (AXS) Method
An-Ni Wang1, Haw-Wen Hsiao
1, Ge-Ping Yu
1,2, Jia-Hong Huang
1
1 Department of Engineering and System Science, National Tsing
Hua University, Hsinchu 300, Taiwan ROC
2Institute of Nuclear Engineering and Science, National Tsing
Hua University, Hsinchu 300, Taiwan ROC
Abstract For polycrystalline thin films and coatings, the
residual stress measurement using X-ray diffraction (XRD) methods
is problematic due to the weak X-ray intensity and the demand of
correct elastic constants, including Young’s modulus and Poisson’s
ratio. The request of accurate elastic constants on thin film under
200 nm is crucial for X-ray stress measurement. Of all techniques,
nanoindentation is often employed due to the simple testing
procedures. However, the X-ray stresses calculated using
nanoindentation-determined elastic constants is often not
consistent with stresses measured from optical curvature, and the
deviation can reach to above 30%. The substrate effect and film
thickness limitation due to indenter probe further increase the
difficulties to obtain accurate elastic constant on thin films
under 200 nm. In our previous researches, we proposed an Average
X-ray Strain (AXS) method to improve the accuracy of the X-ray
measurement of X-ray stress (XRS) and X-ray elastic constants
(XECs) by increasing the sampling volume at several azimuthal
angles. TiN coatings on Si substrate with the thickness of 1.55 um
was successfully measured, where the XRS and XECs are in good
agreement with other techniques. In this research, a simple X-ray
measurement procedure for thin films under 200 nm using AXS method
is proposed. TiN thin film on Si (100) substrate was
selected as the model systems, where the AXS was determined
using cos2sin
2 XRD technique at 7 rotational () angles. The
thickness of TiN coatings were from 2500 nm to 85 nm, observed
by SEM cross-sectional images. The XRS was calculated by
substituting elastic constants from nanoindentation (ENI) in to
the slope of strain from AXS vs. cos2sin
2 plot. The average
effective elastic constants (AEXECs) were attained by combing
AXS with residual stress from wafer curvature method. The
difference between XRS and stress from wafer curvature techniques
is served as an indicator to validate the selection of elastic
constants. The XRS for films above 500 nm showed acceptable
deviation around 33% using AXS with ENI. On the other hand, the XRS
using ENI on films below 200 nm showed large deviation from 221 to
305 % due to the thickness limitation of nanoindentation. By using
ENI from the specimens above 200 nm, the variance was reduced to
53%. The lack of sufficient X-ray sampling volume below 200 nm
could be the cause of the deviation, and the sudden increase of
AEXEC below 200 nm also suggested the insufficient AXS sampling.
Still, AXS could serve as a convenient parameter for X-ray stress
measurement when using proper elastic constant and sufficient
sampling volume.
