A5101749901- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Magnetic properties of thin films
- ZnO doping and properties
- Magnetic and transport properties of perovskites and related materials
- Luminescence Properties of Advanced Materials
- Semiconductor materials and devices
- Advanced Condensed Matter Physics
- Rare-earth and actinide compounds
- Perovskite Materials and Applications
- Metal and Thin Film Mechanics
- Magnetic Properties and Applications
- Ferroelectric and Piezoelectric Materials
- Copper-based nanomaterials and applications
- GaN-based semiconductor devices and materials
- Acoustic Wave Resonator Technologies
- Microwave Dielectric Ceramics Synthesis
- Glass properties and applications
- Magnetic Properties of Alloys
- High-pressure geophysics and materials
- Radiation Detection and Scintillator Technologies
- Superconductivity in MgB2 and Alloys
- Electromagnetic wave absorption materials
- Advancements in Solid Oxide Fuel Cells
- Multiferroics and related materials
Fudan University
2022-2024
University of Hong Kong
2020-2022
National University of Singapore
1996-2005
Epitaxial crystalline yittria-stabilized zirconia (YSZ) oxide films were grown on silicon wafers by the laser molecular beam epitaxy technique. The interface of YSZ film in contact with was found to be atomically sharp and commensurately crystallized without an amorphous layer. An x-ray photoelectron spectroscopy depth profile transmission electron microscopy investigation showed that no SiO2 formed at interface. For a electrical equivalent thickness (teox) 14.6 Å, leakage current is about...
In this paper, the giant tunability of thermal behaviors, i.e., from deterioration to substantial growth, is firmly demonstrated for vibronic luminescence Mn4+ ions in fluoride phosphors. Such peculiar behavior uncovered be associated with excitation a low-frequency phonon bath, and theoretical model involving excitation-wavelength-dependent populations levels temperature-dependent nonradiative recombination processes successfully constructed. Two main governing parameters, namely,...
In applications of superconducting devices, the crystalline texture high-quality thin films is primary importance. The preferred orientation can be essentially controlled by means substrate temperature, . order to study dependence film on different , a series were deposited YSZ substrates on-axis pulsed-laser ablation technique. temperature was varied from while rest growth parameters remained same. Various analytical techniques, including x-ray diffraction, scanning electron microscopy,...
Anomalous thermal behaviors of excitonic luminescence in CsPbBr
Crystalline yttria-stabilized zirconia oxide (YSZ) film was successfully deposited on a silicon wafer without an interfacial amorphous SiO2 layer. The with equivalent thickness teox down to 1.77 nm shows negligible hysteresis and low interface state density, less than 3×1011 cm-2 eV-1. leakage current density for = film, 1.5×10-5 A at 1 V bias voltage, is five orders of magnitude lower that the same thickness. results demonstrate ultra-thin YSZ has sufficient resistivity against formation...
Epitaxial LaNiO3 (LNO) thin films were grown on (001) SrTiO3 substrates by laser molecular-beam epitaxy. The growth process of the LNO was monitored in situ reflection high-energy electron diffraction (RHEED). Clear RHEED patterns and intensity oscillation observed during epitaxial process. morphology studied atomic force microscopy. results show that this method have a nanoscale smooth surface with root-mean-square roughness smaller than 7 nm an area 1×1 μm2. X-ray indicate crystalline...
The yellow luminescence (YL) is a famous acceptor-associated light emission phenomenon in GaN, which technologically important wide-bandgap semiconductor having tremendous applications short-wavelength optoelectronic devices and high-power/high-temperature electronic devices. However, there have been few studies on the broadening lineshape analysis substantial negative thermal quenching of YL band GaN. In this article, large (NTQ) series Si-doped GaN samples observed investigated detail...
The surface morphology and microstructure of laser-ablated Pb(Zr0.52Ti0.48)O3 (PZT) films on a (100) SrTiO3 (STO) substrate at early growth stage are characterized by means atomic-force microscope, x-ray diffraction, high-resolution transmission electron microscopy analysis. STO is found to be very favorable for epitaxial (001) PZT films, which undergo three-dimensional island mode. We observed two-layer structure the film thickness around 40–50 nm when small nuclei/grains merge into large...
The inter-grain extrinsic magnetoresistance (eMR) observed in polycrystalline perovskite manganites has attracted attention recently. Previous efforts aimed at eMR enhancement have concentrated on grain boundary (GB) modification, mainly by insulator doping. In this paper, however, we report our investigations the doping effect of a metal, Ag, phenomenon. La2/3Sr1/3MnO3 (LSMO) thin films were deposited with varying Ag precipitation (001) LaAlO3 different substrate temperatures (Ts) dual-beam...
A reversible structural transition of an epitaxial La(2/3)Sr(1/3)MnO3 film deposited on a LaAlO3 substrate has been investigated by means in situ high-resolution transmission electron microscopy and diffraction, combined with image diffraction calculations. We observe that the crystallographic symmetry can be lowered via beam irradiation, leading to rhombohedral-monoclinic transition. This attributed cooperating effect mismatch stress irradiation-induced thermal stress.
Doping techniques are of great importance in developing new materials and devices. We present here a novel approach for doping impurity thin film by using dual-beam pulsed-laser deposition technique that allows situ controlling under wide range conditions. demonstrated Ag YBa2Cu3O7−δ films the first time observed long bar-like structures with length up to 150 μm as-deposited films, which may have important application fabrication superconductor-normal metal-superconductor Josephson junctions.
Barium hexaferrite (BaM) thin films were deposited on (0001) LiTaO3 substrates by pulsed laser deposition. Effects of the substrate temperature and oxygen gas pressure formation quality these studied. Films at a 800 °C an around 0.23 mbar showed best c axis normal to film plane with locked in-plane orientation. The saturation magnetization Ms anisotropy field Ha measured vibrating sample magnetometer almost same as those reported bulk barium ferrite. Decreasing hinders Ba layer in BaM...