A5036012783- Ferroelectric and Piezoelectric Materials
- Electronic and Structural Properties of Oxides
- Intermetallics and Advanced Alloy Properties
- Multiferroics and related materials
- MXene and MAX Phase Materials
- Magnetic and transport properties of perovskites and related materials
- Advanced Thermoelectric Materials and Devices
- Acoustic Wave Resonator Technologies
- Semiconductor materials and interfaces
- Advanced materials and composites
- Thermal properties of materials
- Semiconductor materials and devices
- Additive Manufacturing Materials and Processes
- Thermal Expansion and Ionic Conductivity
- Bullying, Victimization, and Aggression
- Behavioral and Psychological Studies
- Photorefractive and Nonlinear Optics
- Hydrogen Storage and Materials
- Child and Adolescent Psychosocial and Emotional Development
- Microwave Dielectric Ceramics Synthesis
- Heusler alloys: electronic and magnetic properties
- Dielectric materials and actuators
- Perovskite Materials and Applications
- Psychology of Development and Education
- Advanced Photocatalysis Techniques
Nanyang Technological University
2020-2025
Tokyo Institute of Technology
2013-2019
UNSW Sydney
2011-2014
Materials Science & Engineering
2011-2014
National Institute of Education
2012
Grain boundary engineering (GBE) is a thermomechanical processing strategy to enhance the physical and mechanical properties of polycrystalline metals by purposely incorporating special types grain boundaries—such as twin boundaries (TB)—in microstructure. Because multiple strain-annealing cycles involved, conventional GBE not directly applicable near-net-shape parts, such those produced via additive manufacturing (AM) technology. In this study, we explore different route that leverages TB...
The effect of the heat treatment conditions on constituent phases and electrical properties (Hf0.5Zr0.5)O2 films deposited by metalorganic chemical vapor deposition was investigated. By using a low temperature or short duration for post-heat after deposition, volume fraction tetragonal phase increases, resulting in high dielectric constant. On other hand, monoclinic increased that were heat-treated at higher temperatures exposed to longer duration. ferroelectric with these greatly inferior....
BaTiO3 (BTO) typically demonstrates a strong n-type character with absorption only in the ultraviolet (λ ≤ 390 nm) region. Extending applications of BTO to range fields necessitates thorough insight into how tune its carrier concentration and extend optical response. Despite significant progress, simultaneously inducing visible-light controlled via doping remains challenging. In this work, p-type 600 is realized iridium (Ir) doping. Detailed analysis using advanced spectroscopy/microscopy...
The effect of doping on the thermoelectric properties Half-Heusler (HH) high-entropy alloy (HEA) Ti2NiCoSnSb was studied. Lower thermal conductivity observed with increased Sb doping. Mass scattering by heavy (Ta, Zr) and light (Al) dopants studied to further lower conductivity. Dopants at level up 50% Ti site were A high HH phase content obtained in Zr-doped samples, a low-lattice 1.9 W/(m·K) observed. This value is one lowest reported lattice conductivities alloys. poor solubility Ta led...
We present a theoretical description of the influence misfit strain on mobile defects dynamics in thin strained ferroelectric films. Self-consistent solutions obtained by coupling Poisson's equation for electric potential with continuity equations donor and electron concentrations time-dependent Landau-Ginzburg-Devonshire reveal that Vegard mechanism (chemical pressure) leads to redistribution both charged electro-neutral order decrease effective stress film. Internal fields, built-in...
Cation intermixing at functional oxide interfaces remains a highly controversial area directly relevant to interface-driven nanoelectronic device properties. Here, we systematically explore the cation in epitaxial (001) oriented multiferroic bismuth ferrite (BFO) grown on lanthanum aluminate (LAO) substrate. Aberration corrected dedicated scanning transmission electron microscopy and energy loss spectroscopy reveal that interface is not chemically sharp, but with an of ∼2 nm. The driving...
A combination of atom column-by-column scanning transmission electron microscopy and density functional theory shows how epitaxial strain alters the local electronic structure in mixed phase bismuth ferrite thin films.
We report a study on multiferroic bismuth ferrite (BiFeO3, BFO)-ferromagnetic lanthanum strontium manganese oxide (La0.7Sr0.3MnO3, LSMO) epitaxial interfaces by scanning transmission electron microscopy-energy dispersive spectroscopy (STEM-EDS) and energy-filtered microscopy (EFTEM). Epitaxial (001) oriented LSMO/BFO heterostructures were fabricated titanate (SrTiO3, STO) substrate using pulsed laser deposition (PLD). Different cooling conditions to room temperature (rapid or slow) used...
To investigate the origin of dielectric tunability, epitaxial Bi1.5Zn1.0Nb1.5O7 (BZN) films are grown on a pyrochlore Bi2Ru2O7 conductive layer by metal-organic chemical vapor deposition. The tunability is 41% at 2.5 MV/cm in temperature range 100–300 K, but significantly suppressed below ∼100 suggesting that BZN film due to random dipole contributions. However, non-negligible remains even 4 implying additional factors, such as phonons, contribute tunability.
The polarization behavior of barium titanate (BTO) thin films fabricated using pulsed laser deposition (PLD) on two different electrodes (strontium ruthenate (SRO) and lanthanum strontium manganese oxide (LSMO)) was studied. (0 0 1) (STO) used as the substrate in both samples. BTO films, ∼20 nm thickness, were characterized a range analytical techniques, such atomic force microscopy (AFM), piezoresponse (PFM) transmission electron (TEM). PFM studies reveal significant enhancement response...
Trilayer heterostructures consisting of a ferroelectric bismuth ferrite (BFO) film sandwiched between ferromagnetic lanthanum strontium manganese oxide (LSMO) films were fabricated using pulsed laser deposition. Both BFO thicknesses (20 nm, 5 nm) and cooling rates varied to investigate the role processing parameters on chemistry interfaces. The interfaces investigated dedicated aberration corrected scanning transmission electron microscope (STEM) operated at 100 kV via STEM-high angle...
Abstract This study examined the utility of a school-based, cognitive-behavioural therapy (CBT) programme for academically weak adolescents with at-risk levels aggressive and rule-breaking tendencies. When compared to baseline data, standardized self-report teacher rating scales revealed that symptoms CBT group significantly reduced within normal limits at post-treatment. These gains were also evident 1-month In contrast, behaviour wait-list control was maintained levels. Interviews...
In-plane orientation-controlled Pb(Zr x ,Ti1− )O3 (PZT) films with a thickness of approximately 2 µm and Zr/(Zr + Ti) ratio 0.39–0.65 were grown on (100) Si substrates by pulsed metal–organic chemical vapor deposition (MOCVD). In-plane-oriented epitaxial PZT in-plane random fiber-textured {100} out-of-plane orientation (100)c SrRuO3//(100)c LaNiO3//(100) CeO2//(100) YSZ//(100) SrRuO3/(100)c LaNiO3/(111) Pt/TiO2/SiO2/(100) substrates, respectively. The effects the crystal structure,...
(110)-oriented epitaxial Mg2Si films were grown on (100), (110), and (111) MgO single crystals by RF magnetron sputtering. Two, one, three types of in-plane variants observed for crystals, respectively. In addition, it was also demonstrated that can be (001) Al2O3 substrates using an epitaxially buffer layer. Transmission electron microscopy studies revealed a clear interface between the layer with relationship. This result indicates other MgO.
Ubiquitous oxygen vacancies and mutually correlated Ti3+ defects in ABO3-type perovskite titanate, such as BaTiO3 (BTO), critically impact optoelectronic properties. However, rationally tuning via synthesis routes obtaining insights into their on photocatalytic H2 generation is limited. Herein, the effect of heating as-synthesized BTO an atmosphere at 400 °C for hour activity investigated. Such post-synthesis modification did not induce changes bulk properties BTO, crystalline phase optical...
Bulk Ti-48Al alloy samples were prepared by high energy ball milling (HBM) of elemental powders, followed spark plasma sintering (SPS) the HBM processed powders. The microstructure, phase evolution and mechanical properties bulk studied. resulting TiAl + Ti3Al two possessed an equiaxed fine grain structure, unlike usual lamellar structure produced arc melting. process parameters SPS, e.g., speed, time temperature used to tune fraction, size. A very nanohardness up ~12 GPa was obtained, ~2.4...