材料期刊网

DEPOSITION OF c-BN FILMS AND ADHESION IMPROVEMENT

S.R. Lee , E.S.Byon and Y.-W. Seo 1)Korea Institnte of Machinery and Materials , Changwon 641-010 , Korea 2)V & P International Co. , Ltd , 705-9 , Gozandong , Inchon 405-310 , Korea Manuscript received 26 August 1996)

金属学报(英文版)

Cubic boron nitride (c-BN) films were successfully grown on Si(100)substrates by a helicon wave plasma-assisted chemical vapor deposition technique.The lower limits of rf substrated bias voltage and plasma density for formation of a single phase c-BN film were 350V and 4.5×10~(10) cm~(3),respectively. The grown c-BN films demonstrated a poor adhesion to the substrates. A postannealing treatment at 800℃ C in N_2 atmosphere was found very effective in relieving the compressive stress in the films which were thereby stabilized to improve the adhesion.

关键词: :cubic boron nitride , null , null , null

R & D ACTIVITIES ON AEROSPACE MATERIALS IN KOREA

H.M. Kim(Korea Institute of Machinery and Materials , Korea Manuscript received 26 August 1996)

金属学报(英文版)

This paper briefly reviews research and development programs in Korean aerospace industry,with an emphasis on aircraft materials technology. International collaborations in these areas are outlined and the R & D activities are highlighted against the　background of the national economy.It is shown that the investment from government agencies and large enterprises has led to healthy development of aerospace materials industries in Korea.

关键词: :R & D , null , null , null

压电位移材料电场E3和应变S1的关系

孙清池 , 左孝杰 , 徐庭献 , 王裕斌

兵器材料科学与工程 doi:10.3969/j.issn.1004-244X.2001.03.002

研究了软性铌锑-锆钛酸铝Pb(Sb1/2 Nb1/2)ZrTiO3(简称SN)系及硬性锑锰-锆钛酸铅Pb(Mn1/3 Sb2/3)ZrTiO3(简称MS)系压电陶瓷电场E3和应变S1的关系.压电方程为S1=d31 E3,在弱电场下为线性关系.随着电场增加,压电应变系数d31变大,从而不再是常数.当电场E3增大到某一值时d31有极大值,我们称此电场为饱和电场Es.软性SN三元系压电陶瓷的退极化电场Ed为12.7kV/cm,小于它的矫顽场Ec(13.6kV/cm)以及d31极大值(-457pC/N)时的饱和电场Es(14kV/cm).而硬性MS三元系压电陶瓷的退极化电场Ed和d31极大值(-202pC/N)时的饱和电场Es相等,均为24kV/cm,大于它的矫顽电场Ec(18.6kV/cm).软性SN三元系压电陶瓷在较低的电场下就可产生很大的应变.而硬性MS三元系压电陶瓷可以施加很大的反向电场.

关键词: 压电应变系数D31 , 退极化电场Ed , 矫顽电场Ec , 饱和电场Es , 电滞回线

Studies of the changes of Mn-Y (Y = S, Se, Te) bond lengths R with the Mn composition x in Zn1-xMnxY alloys from optical spectrum data

Journal of Physics and Chemistry of Solids

The changes of Mn-Y (Y = S, Se, Te) bond lengths R with the Mn composition x in the diluted magnetic semiconductors Zn1-xMnxY are calculated from the optical spectra and their pressure shifts. The calculated results suggest that the Mn-Y bond lengths change little with the Mn composition x-much less than expected from lattice parameters as determined by X-ray diffraction. These results are also in good agreement with the observed values obtained from the EXAFS measurements. It appears that for ternary A(1-x)M(x)Y (M denotes the divalent transition-metal ion) alloys the changes of M-Y bond lengths R with the M composition x can be studied from their optical spectrum data. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词: semiconductors;high pressure;crystal fields;luminescence;light;properties;absorption fine-structure;local-structure;dependence;pressure;exafs

Ni液中Y-S平衡的研究

王龙妹 , 杜挺

金属学报

用直接平衡法研究了1500,1550,1600℃Ni液中Y-S平衡关系,测定了钇的脱硫常数lgK_(YS)及Y,S的一阶活度相互作用系数e_S~Y与温度的关系,并进行了有关的热力学计算。由测得的数据算出Ni液中YS的标准生成自由能△G_((Y)S),钇的标准溶解自由能△G_((Y)(l)→[Y]Ni),活度系数γ_Y~o,以及钇的克原子分数自相互作用系数∑_Y~Y和百分浓度自相互作用系数e_Y~Y与温度的关系。 对于反应[Y]_(Ni)+[S]_(Ni)=YS_(s) △G_((Y)S)=-215000+95.53T(cal/mol)脱硫常数: lgK_(YS)=-47000/T+20.86 e_S~Y=-350200/T+179 △G_((Y)(l)→[Y]Ni)=126200-79.31T(cal/mol) lgγ_(Y)=27584/T-15.151 ∑_Y~Y=-127T05/T+69.79 e_Y~Y=-364.8/T+0.2018

关键词:

The tendency of the market and technology of the magnetic materials in Korea

C.O.Kim , Y.Li

材料科学技术（英文）

关键词:

The Tendency of the Market and Technology of the Magnetic Materials in Korea

材料科学技术（英文）

关键词:

THERMODYNAMIC PROPERTIES Cu-Ce-S AND Cu-Y-S LIQUID SOLUTIONS

LI Guodong , D U Ting , Central Iron and Steel Research Institute , Ministry of Metallurgical Industry , Beijing , China LI Guodong , Department No.16 , Central Iron and Steel Research Institute , Ministry of Metallurgical Industry , Beijing , 100081 , China

金属学报(英文版)

The thermodynamic properties of Cu-Ce-S and Cu-Y-S liquid solutions were studied by the chemical equilibrium technique at 1200℃. The equilibrium constants and the standard free energies of formation of CeS and YS were determined for the reactions: CeS=[Ce]+[S] and YS = [Y]+[S] . For the solution of Ce_(1) and Y_(l) in pure Cu according to the reactions: Ce_(1)= [Ce] and Y_(1)= [Y] , the standard free energies of solutions were obtained. The first order and second order interaction coefficients between solute elements as well as the activity coefficients γ_(Ce)~0 and γ_Y~0 in liquid Cu were also determined.

关键词: Cu-Ce-S system , null , null

(S)TEM study of different stages of Ti-45Al-8Nb-0.2W-0.2B-0.02Y alloy oxidation at 900 degrees C

Corrosion Science

The oxidation process of Ti-45Al-8Nb-0.2W-0.2B-0.02Y (at%) can be divided into three stages during 100 h at 900 degrees C. The change of ion diffusion path leads to the discontinuity of the oxidation curve between the second and third stage. Different stages of oxidation morphology have been investigated combined with TEM and STEM. AlNb2 phase forms at the interface of oxide scale/base alloy. Contrary to a continuous formation of 'x' phase in gamma-TiAl with Nb free at the interface of oxide scale/base alloy. AlNb2 phase hinder continuous 'x' phase formation, which can promote TiAl oxidation protection. (c) 2007 Elsevier Ltd. All rights reserved.

关键词: alloy;STEM;oxidation;gamma-titanium aluminide;high-temperature air;tial-based alloys;intermetallic alloys;ternary-system;behavior;phase;scales;si

基于ZnTe1-xYx(Y=O,S,Se)中间带光伏材料光电性能的第一性原理研究

吴孔平 , 鲁开林 , 蒋建彗 , 顾书林 , 叶建东 , 汤琨 , 朱顺明

材料导报 doi:10.11896/j.issn.1005-023X.2014.24.030

采用基于密度泛函理论框架下的第一性原理方法计算了高失配三元合金ZnTe1-xYx(Y=O,S,Se)的能带结构、电子特性与光学性能.通过对半导体态密度的计算证实了在闪锌矿结构的ZnTe中掺杂O、S或Se原子可能得到独立的中间带结构,该结构可提高光伏材料对能量低于母体半导体带隙光子的吸收效率.研究结果表明,中间带在ZnTe1-x(x中是由掺杂的O原子的2p态与处于导带的Zn原子的4s态耦合而成,符合能带反交叉模型.另外,与ZnTe1-xS和ZnTe1-xSex相比,随着掺杂O浓度的变化,ZnTe1-xq的中间带表现出较高的稳定性主要是因为O与Te之间存在最大的电负性差.

关键词: 中间带(IB) , 电负性差 , 电子能带结构 , 光学性质