Physical Review B
In order to understand the unusually large value of zero-field splitting D for the axial Fe3+ center in a KTaO3 crystal, Zhou made two assumptions in his recent report [Phys. Rev. B 42, 917 (1990)]. In this Comment we will show that his assumption II is qualitatively reasonable, whereas assumption I is unnecessary and doubtful.
关键词:
electric-field;srcl2
X.B. Tian
,
X.F. Wang
,
A.G. Liu
,
L.P. Wang
,
S. Y. Wang
,
B. Y. Tang and P. K. Chu 1)Advanced Welding Production & Technology National Key Laboratory
,
Harbin Institute of Technology
,
Harbin 150001
,
China 2)Department of Physics & Materials Science
,
City University of Hong Kong
,
China
金属学报(英文版)
The research on plasma immersion ion implantation has been conducted for a little over ten years. Much is needed to investigate including processing technlogy, plasma sheath dynamics, interaction of plasma and surface, etc. Of the processing methods elavated temperature technique is usually used in PIII to produce a thick modified layer by means of the thermal diffusion. Meanwhile plasma ion heating is more recently developed by Ronghua Wei et al[1]. Therefore the temeperature is a critical parameter in plasma ion processing. In this paper we present the theoretical model and analysize the effect of imlantation voltage, plasma density, ion mass,etc on the temperature rise.
关键词:
plasma immersion ion implantation
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null
,
null
夏小建
量子电子学报
doi:10.3969/j.issn.1007-5461.2009.06.010
采用Wei-Norman方法,求出含时变电压源的介观LC电路随时间演化的精确解,应用相空间准概率分布函数,研究了时变电源作用下介观LC电路相干态的量子特性,结果表明此函数是一个二维运动的Gauss波包,其中心电量和磁通呈余弦和正弦变化.
关键词:
量子光学
,
LC回路
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介观电路
,
相干态
,
量子态演化
,
相空间的准概率分布函数
Journal of Physics and Chemistry of Solids
The layered ternary ceramics Ti3SiC2 and Ti3AlC2 are isostructural and can form Ti3Si1-xAlxC2 solid solutions combining the advanced properties of both compounds [H.B. Zhang, Y.C. Zhou, Y.W. Bao, M.S. Li, Improving the oxidation resistance of Ti3SiC2 by forming a Ti3Si0.90Al0.1C2 solid solution, Acta Mater. 52 (2004) 3631-3637; E.D. Wu, J.Y. Wang, H.B. Zhang, Y.C. Zhou, K. Sun, Y.J. Xue, Neutron diffraction studies of Ti3Si0.9Al0.1C2 compound, Mater. Lett. 59 (2005) 2715-2719; J.Y. Wang, Y.C. Zhou, First-principles study of equilibrium properties and electronic structure of Ti3Si0.75Al0.25C2 solid solution, J. Phys.: Condens. Matter 15 (2003) 5959-5968; Y.C. Zhou, J.X. Chen, J.Y. Wang, Strengthening of Ti3AlC2 by incorporation of Si to form Ti3Al1-xSixC2 solid solutions, Acta. Mater. 54 (2006) 1317-1322]. In the present work, the solid solutions of Ti3Si1-xAlxC2 (x = 0, 0.25, 0.33, 0.5, 0.67, 0.75, 1) are investigated by first-principle calculations based on pseudo-potential plan-wave method within the density functional theory framework. The results show that as Al content increases in the solid solution, all the bonds have weakened to certain extents, which lead to an unstable structure both energetically and geometrically. The calculated results are compared and discussed with the reported data for the Ti3Si1-xAlxC2 solid solutions. (c) 2007 Elsevier Ltd. All rights reserved.
关键词:
ceramics;ab initio calculations;electronic structure;electrical;conductivity;oxidation behavior;mechanical-properties;ti3sic2;temperature;ti3alc2;air;si
WEI Jihe Xi'an Institute of Metallurgy and Construction Engineering
,
China.
材料科学技术（英文）
The oxidation of alloying elements during the ESR of stainless steel has been studied. The model previously developed by WEI and Mitchell for the chemical reactions and mass transfer processes during ESR was applied to the remelting of the high Cr steel 1Cr18Ni9(Ti).The laboratory data for the unsteady state A.C.ESR were analyzed and dealt with by the model.When the remelting process reached a steady state,an oxidant(Fe_2O_3 powder)or a deoxidant(Ca-Si powder or metallic Ca)was added to the slag bath.The results showed that this model is applicable to the remelting of stainless steel rather precisely, and it is expected that the model may offer a reliable basis for the control of composition during practical ESR of high alloy steel. Also,the oxidation of Cr in the steel must be noticed when its content is high;but it is entirely possible to adjust the Cr content of ingot within a considerable range,using a special technique by means of the slag-metal reactions during the remelting.
关键词:
ESR
,
null
,
null
,
null
,
null
ZHOU Jiankun LIU Xianghuai CHEN Youshan WANG Xi ZHENG Zhihong HUANG Wei ZOU Shichang Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
China
金属学报(英文版)
The TiN films were synthesized with an alternate process of depositing titanium from a E-gun evaporation source and 40 keV N~+ bombarding onto the target.It is shown from the composi- tion analysis and structure investigations using RBS,AES,TEM,XPS and X-ray diffraction spectrum that the formed fihns are mainly composed of TiN phase with grain size of 30—40 nm and without preferred orientation,the nitrogen content in the film is much less than that in case without N~+ bombarding,and an intermixed region about 40 nm thick exists between the film and the substrate.The films exhibt high microhardness and low friction. ZHOU Jiankun,Ion Beam Laboratory,Shanghai Institute of Metallurgy,Academia Sinica, Shanghai 200050,China
关键词:
TiN film
,
null
Physical Review B
The assignment of the absorption spectrum of Y3Fe5O12 (YIG) made by Scott et al. [Phys. Rev. B 10, 971 (1974)] is shown to be incorrect and a new one is made by diagonalizing the complete cubic crystal-field matrices for d5 ions, involving spin-orbit interaction, given by Zhou et al. [Phys. Rev. B 44, 7499 (1991)]. The Racah parameters B and C, the crystal-field parameter Dq, and the spin-orbit coupling coefficient zeta are determined (in units of cm-1) as B = 783.3(530), C = 2928(3220), Dq = 1336(1300), zeta = 395 for octahedral Fe3+, and B = 606.1(705), C = 2696(2730), Dq = -1117.3(560), zeta = 335 for tetrahedral Fe3+, where the numerals in parentheses are the values adopted by Scott et al. Furthermore, the cubic zero-field splitting parameter a of Fe3+ in YIG is calculated to be a(oct) = 156 X 10(-4) cm-1 and a(tet) = 58.6 X 10(-4) cm-1. The value for a(oct) differs from the value of 189 X 10(-4) cm-1 found for Fe3+ in Y3Ga5O12:Fe3+. These results support speculations made by Geschwind [Phys. Rev. 121, 363 (1961)].
关键词:
fe3+;mn2+
