材料期刊网，材料期刊，材料类期刊，材料期刊投稿

A condition for local moment formation in metals derived by Stoddart and March (Ann. Phys. NY 1972 64, 174) is first used to discuss the ferromagnetism of body-centred-cubic Fe. A less detailed discussion is also added on Ni and Co. This leads into a treatment of the nonlinear response of such 3d ferromagnets to dilute substitutional impurities. Antiferromagnets responding to local changes in the exchange field caused by such impurities are also studied, Mn in Cr being one such system discussed. The paper concludes with a brief summary of clusters of transition metal atoms, with most attention devoted to Cr and to Mn.

关键词:

Mechanical Properties of Si and Some d-electron Metals: Force Laws, Electron Correlation and Bond-breaking

N.H.March

材料科学技术（英文）

The coordination-dependent force field of Tersoff for covalently bonded Si has been used to calculate the cleavage force as a function of interplanar separation and hence to estimate surface energies. This force field is already fitted to density functional results. The relation to bond-breaking and electron correlation will be emphasized. Finnis-Sinclair-type many-body potentials have then been used to treat some d-electron metals. In particular, results for cleavage force in bcc Fe will be presented, and also some calculations as two perfectly planar Fe surfaces are `rubbed together' at different interplanar separations. Finally, lattice dynamical models for the steady-state propagation of a screw dislocation, and then of a crack, will be used, again within a bond-breaking type of force field. For the screw dislocation propagation, a solitary wave equation is shown to follow in the ‘almost continuum' limit. Energy radiated by phonons as the dislocation moves can thereby be calculated.

关键词:

March-Dollase函数在计算铜带择优取向上的应用

李英楠 , 李凤华 , 樊占国 , 李成山 , 卢亚锋

材料导报

根据XRD衍射图谱分析了Cu加工的择优取向行为,采用极密度相除的方法对March-Dollase函数求解过程进行了简化,使之可以直接根据XRD衍射图谱的若干峰值算出r值,间接计算择优取向的体积分数.把实测样品的XRD衍射花样与由Rietveld程序根据March-Dollase函数反推的XRD衍射花样进行对比,发现当r值小于0.45时两者符合良好,说明在此条件下(r<0.45)本数值计算方法对r值的计算准确可靠,能够估算择优取向体积分数.

关键词: 冷轧 , 再结晶 , March-Dollase函数 , 择优取向

H3O+(H2O)n(n=0～4)与甲醇、乙醇反应的实验研究

李建权 , 程平 , 王鸿梅 , 王占新 , 储焰南 , 周士康

量子电子学报 doi:10.3969/j.issn.1007-5461.2004.03.005

在流动余辉质谱装置上,利用He的空心阴极放电产物与H2O反应制备了反应物离子H3O+(H2O)n(n=0～4),并观察了H3O+(H2O)n(n=0～4)与CH3OH、C2H5OH反应的产物离子,对它们进行了归属,分析了各种产物离子形成的离子-分子反应机制.

关键词: 光谱学 , 流动余辉质谱 , 甲醇 , 乙醇

C-H-N体系生长金刚石薄膜

万永中 , 张志明 , 沈荷生 , 何贤昶 , 张卫 , 王季陶

无机材料学报

通过热力学分析从理论计算上给出了C－H－N体系中低压生长金刚石的三元相图．该相图中存在金刚石生长区．不同温度和压强下金刚石生长区几乎都位于CH₄－N连线以下，并且随衬底温度的改变而有显著的变化．随着氮含量的增加，金刚石生长区向碳含量减少的方向移动．使用该相图对优化添加含氮气源生长金刚石的实验条件提供了理论依据．

关键词: 金刚石 , diamond , phase diagram , nitrogen

C-H-N体系生长金刚石薄膜

万永中 , 张志明 , 沈荷生 , 何贤昶 , 张卫 , 王季陶

无机材料学报 doi:10.3321/j.issn:1000-324X.1999.06.002

通过热力学分析从理论计算上给出了C-H-N体系中低压生长金刚石的三元相图.该相图中存在金刚石生长区.不同温度和压强下金刚石生长区几乎都位于CH4-N连线以下,并且随衬底温度的改变而有显著的变化.随着氮含量的增加,金刚石生长区向碳含量减少的方向移动.使用该相图对优化添加含氮气源生长金刚石的实验条件提供了理论依据.

关键词: 金刚石 , 含氮气源 , 相图 , 化学气相淀积

Effect of Li(3)N additive on the hydrogen storage properties of Li-Mg-N-H system

Journal of Materials Research

The effect of Li(3)N additive on the Li-Mg-N-H system was examined with respect to the reversible dehydrogenation performance. Screening Study with varying Li(3)N additions (5, 10, 20, and 30 mol%) demonstrates that all are effective for improving the hydrogen desorption capacity. Optimally, incorporation of 10 mol% Li(3)N improves the practical capacity from 3.9 wt% to approximately 4.7 wt% hydrogen at 200 degrees C, which drives the dehydrogenation reaction toward completion. Moreover, the capacity enhancement persists well over 10 de-/rehydrogenation cycles. Systematic x-ray diffraction examinations indicate that Li(3)N additive transforms into LiNH(2) and LiH phases and remains during hydrogen cycling. Combined structure/property investigations suggest that the LiNH(2) "seeding" should be responsible for the capacity enhancement, which reduces the kinetic barrier associated with the nucleation of intermediate LiNH(2). In addition, the concurrent incorporation of LiH is effective for mitigating the ammonia release.

关键词: complex hydrides;improvement;mixtures;imides;amide;h-2

N2H4·H2O水热体系ZnO微晶的结晶特性

刘长友 , 谷智 , 王涛 , 查钢强 , 介万奇

功能材料

研究了低浓度（0.01～0.20mol/L）N2H4.H2O条件下ZnO微晶的低温水热结晶特性。N2H4.H2O弱碱性和N2H5＋吸附配位性影响ZnO微晶的形核和各晶面的生长速率。随着N2H4.H2O浓度的提高,ZnO微晶分别呈板条状、六角片状和六角棒束状。碱性分散剂和超声的分散作用影响主要在成核阶段;受分散剂弱碱性的影响,0.20mol/L N2H4.H2O显现出强的还原性,N2气泡模板生长机制使所制ZnO微晶呈六角管状晶须束。

关键词: 氧化锌 , 水热合成 , 结晶习性 , 水合肼

微波放电研究大气中NO+和H3O+(H2O)n离子的形成过程

程平 , 王鸿梅 , 李建权 , 张为俊 , 曹德兆 , 储焰南

量子电子学报 doi:10.3969/j.issn.1007-5461.2003.03.006

利用微波放电电离质谱装置,分别通过N2与O2、水蒸气与空气的微波放电,产生了大气中存在的NO+和H3O+.(H2O)n离子,动力学过程的分析和讨论表明这几种离子是由大气中的初始反应离子N+2、N+、O+2、O+与周围环境中的原子、分子经过一系列的离子-分子反应产生的.这一结论也同时模拟了大气中NO+和H3O+.(H2O)n的形成过程.

关键词: 微波放电 , 大气 , 离子化学