Shihong XU Pengshou XU Mingrong JI Xianming LIU Maosheng MA Jingsheng ZHU Yuheng ZHANG Structure Research Laboratory
,
University of Science and Technology of China
,
Hefei
,
230026
,
ChinaZhenjia XU Institute of Semiconductor
,
Academia Sinica
,
Beijing
,
100083
,
China
材料科学技术（英）
The alkali-metal Na adsorption on Si(100)2×1 surface and its promoted oxidation and Si oxide growth have been investigated by means of thermal desorption,work function,Auger electron spectroscopy and photoemission electron spectroscopy.The experimental data showed that there was a new state,interface electron state,near the Fermi level after the deposition of Na atoms.It was found that the presence of Na always caused an increase of the oxygen initial uptake whereas the promotion of Si oxide growth was observed only at the coverage of Na greater than 0.5 ML.A new mechanism of Na-promoted Si oxide growth is suggested in this paper.
关键词:
adsorption
,
null
,
null
,
null
Journal of Applied Physics
Amorphous BC2N powders were prepared by mechanical milling with hexagonal boron nitride and graphite as starting materials. A bulk amorphous BC2N compound was produced by sintering the as-milled amorphous BC2N powders in a vacuum of 10(-5) Torr at a temperature of 1470 K. The conductivity measurement for the bulk amorphous BC2N compound showed that it behaves as a semiconductor with band gap energy of 0.11 eV for temperatures ranging from room temperature to 560 K and a semimetal for temperatures between 560 and 740 K. The mechanism of the formation of the amorphous BC2N powders is discussed. (C) 1998 American Institute of Physics.
关键词:
bc2n
Communications in Theoretical Physics
Ground state energies for shallow states of donor impurities at certain idealized defective isotropic semiconductor surfaces are calculated variationally for GaAs surfaces with electrons confined within the semiconductor. Calculations show that impurity states with donor ions located at parts projecting out of surfaces have lower ground state energies than those with ions located at parts sunk into surfaces.
关键词:
si;ge
Applied Physics Letters
The dielectric resonance and multiple magnetic resonances which correspond to multiple microwave absorptions in the 2-18 GHz range have been studied in the composite Fe/TiO(2). The Fe grain size is found to have great impact on the dielectric resonance in this metal-semiconductor composite. The polarization mechanism is attributed to interfacial polarization. The multiple magnetic resonances can be ascribed to the natural resonance and exchange resonances, which can be explained by Aharoni's exchange resonance theory. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3496393]
关键词:
ferromagnetic particles;carbon nanotubes;absorption;permeability
Gang JI
,
Shishen YAN
,
Yanxue CHEN
,
Qiang CAO
,
Wei XIA
,
Yihua LIU
,
Liangmo MEI
,
Ze ZHANG
,
null
材料科学技术（英）
2×(FeNi/CoZnO)/ZnO/(CoZnO/Co) ×2 spin-injection devices were prepared by sputtering and photo-lithography. In the devices, two composite magnetic layers 2×(FeNi/CoZnO) and (CoZnO/Co) ×2 with different coercivities were used to fabricate the ZnO-based semiconductor spin valve. Since the CoZnO ferromagnetic semiconductor layers touched the ZnO space layer directly, the significant spin injection from CoZnO into ZnO was observed by measuring the magnetoresistance of the spin-injection devices. The magnetoresistance reduced linearly with increasing temperature, from 1.12% at 90 K to 0.35% at room temperature.
关键词:
Spin injection
,
磁电阻
,
铁磁性半导体
Physical Review B
Longitudinal electron transport is investigated for a long-period semiconductor superlattice in the presence of a magnetic field applied along the growth direction of the superlattice. It is shown that the longitudinal magnetoresistance exhibits a complicated dependence on the magnetic-field strength. In contrast with the conventional Shubnikov-de Haas oscillations, the magnetoresistance shows periodic oscillations only in the region of low reciprocal magnetic field.
关键词:
magnetoresistance
Journal of Applied Physics
A CO2 sensor made of nano crystalline CuO-BaTiO3 semiconductor, which has a giant capacitance effect, is designed based on the principle of the physical effect in the nano cluster. After an experimental investigation of its microstructure, the correlation between the quantum size effect and the giant capacitance effect is suggested. The characteristic physical quantities relating to the giant capacitance effect of the sensor are studied systematically with the aid of a gas detector. The quantum size effect is introduced as an interpretation for the mechanism of the giant capacitance effect and a model is proposed for describing the giant capacitance effect of the sensor. (C) 2000 American Institute of Physics. [S0021-8979(00)05020-9].
关键词:
mixed-oxide capacitor;transitions;powders
Scripta Materialia
A photoconductive semiconductor switch (PCSS) based on an individual ZnS nanobelt (NB) was investigated. Under ultraviolet light (280 nm), the current-voltage curve shows that this PCSS is of high photosensitivity (similar to 10(4)), and the response time spectrum shows that this PCSS has a fast response (typical rise time 0.07 s and decay time 0.12 s) and a high-voltage response (6.7 V). Oxygen chemisorption is responsible for the improved photoconductive properties. This PCSS is a promising candidate for future integration. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词:
Photoconductive;ZnS;Nanobelt;Ultraviolet light;Photosensitivity;nanowires;devices
