A5029204052- High-pressure geophysics and materials
- Inorganic Fluorides and Related Compounds
- Luminescence Properties of Advanced Materials
- Ferroelectric and Piezoelectric Materials
- Acoustic Wave Resonator Technologies
- Microwave Dielectric Ceramics Synthesis
- Electronic and Structural Properties of Oxides
- Boron and Carbon Nanomaterials Research
- Advanced Semiconductor Detectors and Materials
- Quantum Dots Synthesis And Properties
- ZnO doping and properties
- Semiconductor Quantum Structures and Devices
- Force Microscopy Techniques and Applications
- 2D Materials and Applications
- Iron-based superconductors research
- MXene and MAX Phase Materials
- Energetic Materials and Combustion
- Multiferroics and related materials
- Gas Sensing Nanomaterials and Sensors
- Solid-state spectroscopy and crystallography
- Electrical and Thermal Properties of Materials
- Advanced Photocatalysis Techniques
- Chalcogenide Semiconductor Thin Films
- GaN-based semiconductor devices and materials
- Electrical Contact Performance and Analysis
Jiaying University
2024
Jilin Normal University
2013-2020
Jilin University
2010-2015
State Key Laboratory of Superhard Materials
2010-2011
Jilin Medical University
2010
The improvement of ferromagnetic properties is critical for the practical application multiferroic materials, to be exact, BiFeO₃ (BFO). Herein, we have investigated evolution in structure and morphology Ho or/and Mn-doped thin films related diversification behavior. BFO, Bi0.95Ho0.05FeO₃ (BHFO), BiFe0.95Mn0.05O₃ (BFMO) Bi0.95Ho0.05Fe0.95Mn0.05O₃ (BHFMO) are synthesized via conventional sol-gel method. Density, size phase crucial optimize properties. Specifically, under applied magnetic...
A pressure induced semiconductor-semimetal phase transition on tungsten diselenide has been studied using in situ electrical resistivity measurement and first-principles calculation under high pressure. The experimental results indicate that the takes place at 38.1 GPa. calculations performed by CASTEP code based density functional theory illustrate indirect band gap of WSe2 vanishes 35 GPa, which an isostructural from semiconductor to semimetal WSe2. According dependence partial states,...
The electronic structure of TiS2 and its transport properties under high pressure have been studied using first-principles calculation in situ parameters measurement. Both the theoretical experimental results support conclusion that is a semimetal rather than semiconductor maintains semimetallic behavior pressure. Although there no significant change density state at Fermi level up to 20 GPa, drastically around 15 manifested by slope resistivity concentration versus curves. This response may...
A method for in situ Hall effect measurement under high pressure was developed on a diamond anvil cell. The electrode accurately integrated one with regular shape. uniform and strong magnetic field introduced into the sample zone. voltage errors brought by some negative effects during were well eliminated. correction factor of coefficient, nonpoint contact between sample, 4.51%. error did not exceed 1%. carrier character ZnTe powders studied up to 23 GPa. evolution conductivity explained...
Two-electrode configuration was developed for in situ electrical impedance detecting on diamond anvil cell under high pressure. The metal gasket used as one electrode and the risk coming from short between sample interside wall of eliminated. evaluated proved to be effective by measuring electric nanocrystalline ZnS
Synchrotron X-ray diffraction (XRD) is performed on BaF2 nanoparticles to study the structural phase transition up about 30 GPa under ambient temperature. We observed that cubic structure in stable 6.8 GPa, a level much higher than bulk BaF2. Pressure-induced amorphization (PIA) occurs compression, which results high-density amorphous (HDA) form. Upon pressure release, low-density (LDA) form maintained at conditions. This first demonstrate PIA and polyamorphism exist nanomaterials finite...
Abstract The resistivity of ZnTe powders has been measured under high pressure up to 29 GPa and temperature ranged from 303.0 403.0 K by using a diamond anvil cell. changed discontinuously at 9.5 13.1 GPa, corresponding the phase transitions zinc blende cinnabar then Cmcm structure. decrease activation energy one order magnitude indicates deep‐to‐shallow transition acceptor levels 6.7 GPa. decreases with increasing semiconducting character in phase. slightly increasing, indicating that this...
Calcium fluoride (CaF₂) nanoparticles with various terbium (Tb) doping concentrations were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and alternating current (AC) impedance measurement. The original shape structure of CaF₂ retained after doping. In all the samples, dominant charge carriers electrons, F- ion transference number increased increasing Tb concentration. defects in grain region considerably contributed to transportation process. When...
The structural phase transition and compressibility of CaF2 nanocrystals with size 23 nm under high pressure were investigated by synchrotron X-ray diffraction measurement. A pressure-induced fluorite to α-PbCl2-type starts at 9.5 GPa completes 20.2 GPa. phase-transition is lower than that 8 closer bulk CaF2. Upon decompression, the structure co-exist ambient pressure. modulus B0 for are 103(2) 78(2) GPa, which both larger those exhibit obviously higher incompressibility compare Further...
The charge transport behavior of barium fluoride nanocrystals has been investigated by <italic>in situ</italic> impedance measurement up to 23 GPa.
The ionic transportation and dielectric properties of YF₃:Eu3+ nanocrystals are investigated by AC impedance spectroscopy. ion diffusion coefficient conductivity increase along with the doping concentration reach their highest values at 4% Eu3+. difference radius between Eu3+ Y3+ leads to structural disorder lattice strain, which deduces before doping; then interaction neighboring ions is dominated, results in difficulty migration decreases conductivity. strong dispersion permittivity low...
Abstract An investigation of TiS 2 electronic structure was conducted using a first‐principles calculation based on density functional theory (DFT). The results showed that there is indirect S 3p ‐Ti 3d band overlaps in ground . measurements resistivity and Hall effect were used to characterize the electrical transport behavior under state. Both theoretical experimental supported within state semimetal (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The high-pressure transport behavior of CaF2 nanoparticles with 3 mol% Tb concentrations was studied by alternate-current impedance measurement. All the electrical parameters vary abnormally at approximately 10.76 GPa, corresponding to fluorite-cotunnite structural transition. substitution Ca2+ Tb3+ leads deformation in lattice, and finally lowers transition pressure. F− ions diffusion, electronic transport, charge-discharge process become more difficult rising In process, defects grains...
We report on the intriguing electrical transport properties of compressed CaF2 nanocrystals. The diffusion coefficient, grain and boundary resistances vary abnormally at about 14.37 GPa 20.91 GPa, corresponding to beginning completion Fm3m–Pnma structural transition. Electron conduction ion coexist in process electron is dominant. transference number Fm3m Pnma phases increases with pressure increasing. As rises, F− electronic processes become more difficult. Defects grains play a dominant...
Abstract Carrier behavior of CaB 6 powders was investigated by using in situ Hall effect measurement under high pressure and resistivity property detected low temperature with microcircuit fabricated on diamond anvil cell. analyzed carrier concentration coefficient. The variation defects the grain boundary region lead coefficient decompression process are much lower than that compression process. depended at various pressures indicated has a typical metallic pressure.
With in situ electrical resistivity and Hall effect measurement, the transport properties carrier behavior of β-HgS under high pressure are investigated up to 32.9 GPa. The changes discontinuously at 5.4, 14.6, 25.0 These discontinuities correspond phase transitions from zinc blende cinnabar, then rock salt structure. For structure, decrease concentration increase mobility indicate that originally overlapped valence band conduction separate with pressure. phase, ionized impurity leads
By use of electrical field analysis method, the accuracy resistivity measurement with van der Pauw method in a diamond anvil cell (DAC) was investigated for situation that sample and gasket were electrically shorted. It is revealed metal could not be used DAC if inside wall chamber insulated. When shorted area less than 20% chamber, relative error smaller 10%. Once exceeded 25%, increased rapidly.
Abstract We have synthesised two kinds of graphitic carbon nitride (g-C 3 N 4 ) through a pyrolysis process involving urea and melamine. The obtained products were characterised by means X-ray diffraction, scanning electron microscopy, transmission Fourier transform infrared spectroscopy, photoelectron UV–vis diffuse reflection nitrogen adsorption–desorption. product derived from the shows mesoporous honeycomb-like nanosheet structure (denoted h-g-C ): compared with bulk melamine b-g-C ),...
We investigate the carrier behavior of HgTe under high pressures up to 23 GPa using in situ Hall effect measurements. As phase transitions from zinc blende cinnabar, then rock salt, and finally Cmcm occur, all parameters change discontinuously. The conductivity variation compression is described by parameters. For phase, both decrease concentration increase mobility indicate overlapped valence band conduction separates with pressure. Pressure causes an hole cinnabar which leads carrier-type...
The charge transport behavior of strontium fluoride nanocrystals has been investigated by in situ impedance measurement up to 35 GPa. It was found that the parameters changed discontinuously at each phase transition. carriers SrF2 include both F ions and electrons. In phase, pressure makes electronic easier, while it more difficult Pnma phase. defects grain boundaries dominate process. Pressure could make charge–discharge processes much but