冯其明
,
陈远道
,
卢毅屏
,
陈云
,
欧乐明
,
张国范
中国有色金属学报
采用基于密度泛函-赝势的量子化学方法研究了一水硬铝石(α-AlOOH)晶体及其(010)表面的原子和电子结构.研究表明: GGA-PBE几何优化得到的晶体结构参数与实验测定数据相符; 通过体相原子间重叠布局分析确定了α-AlOOH(010)表面最容易解理的位置; 通过一系列测试计算选择原子层数为4, 真空层厚度为7.5的slab模型模拟α-AlOOH(010)表面, 结果表明表面原子发生弛豫, 且驰豫表面的表面能为0.491J/m2; 根据表面态密度分析、表面原子排布情况和前线轨道理论推测, 阴离子捕收剂很难与一水硬铝石(010)的表面Al原子间发生化学作用, 却容易与水硬铝石(010)的表面H原子相互作用.
关键词:
密度泛函理论
,
一水硬铝石(α-AlOOH)
,
体相
,
(010)表面
刘伟
,
赵国升
,
常立民
,
安茂忠
硅酸盐通报
开发高效稳定的具有高活性｛010｝晶面单斜钒酸铋基光催化剂是当前的研究热点之一。本文综述了具有高活性｛010｝晶面单斜钒酸铋以及改性具有高活性｛010｝晶面单斜钒酸铋光催化剂的研究进展，着重介绍了光催化剂在制备方法和应用方面所取得的成果。
关键词:
钒酸铋
,
活性晶面
,
{010}
,
光催化剂
Computational Materials Science
The discrete variational method within the framework of density functional theory is used to study the electronic structures of the < 100 > {010}, < 100 > {011} and 1/2 < 111 > {011} edge dislocations in bcc Fe, and the density of states, the charge density, the structural energy and the interatomic energy are obtained. The results show that localized electronic states exist in the cores of the (10 0) 10 10 1 and < 100 > {011} edge dislocations, but not in the 1/2 < 111 > {011} edge dislocation. The features of the < 100 > {010} edge dislocation are similar to those of the < 100 > {011} edge dislocation, but different from those of the 1/2 < 111 > {011} edge dislocation. In addition, there is an intrinsic hindrance of the lattice to the dislocation motion, namely, an effect of trapping of lattice on the dislocation. For the 1/2 < 111 > {011} edge dislocation, the interaction between the atoms along the slip direction is much stronger than that normal to the slip direction. However, in the < 100 > type edge dislocation, the interatomic bonds along and normal to the slip direction have almost the same strength, and the bond is even stronger normal to the slip direction in the < 100 > {011} edge dislocation. The results show that the motion of the 1/2 < 111 > edge dislocation may be easier than that of the < 100 > edge dislocation under a stress field. (c) 2006 Elsevier B.V. All rights reserved.
关键词:
edge dislocation;first-principles calculations;electronic structure;transition-metals;core structure;hcp metals;energy;impurities;alloys;nickel;ni3al
X.Y. Pang Z.Q. Liu S.Q. Wang J.K. Shang
材料科学技术（英文）
Density functional theory was employed to investigate the bismuth segregation at Cu/Cu3Sn(010) interface. Five initial constructions were introduced by adopting the adhesion energy criterion. Among them, the so-called "between-Cu" construction in which the interface Cu atoms of Cu slab locate along Cu-Cu bond direction in Cu3Sn slab was found to be the most energy-favored at an adhesion energy of 1.96 J/m2. Based on this construction, five possible segregation sites were examined, and the most likely segregation site was determined with adhesion energy as low as 1.06 J/m2, which was almost half of the initial one. Comparing with other sites' adhesion energies, it was concluded that size effect took a large part in embrittlement. The analyses of atomic structure and electronic density revealed that the slabs shifted away from interfaces due to bismuth segregation, and the atoms around Bi atom were pressed away. This calculated work agreed qualitatively with reported experimental results.
关键词:
First-principles calculation
,
segregation
,
Bismuth
,
interface
,
SnBi solder.
Journal of Nanoscience and Nanotechnology
Structural changes of Au clusters respectively containing 603 and 675 atoms with their (100) facts supported on MgO(010) surfaces at 5 K have been investigated by molecular-dynamics simulations on the atomic interchange potentials of the metal/MgO interface, which parameters are from the Ab initio energies using Chen-Mobius inversion method. As the interaction time evolves, the structural changes accompanying with atom movements are determined by decomposing peaks of pair distribution functions (PDFs) according to the pair analysis (PA) technique, and local structure patterns are identified for the supported clusters. It is shown that there exist deformation processes of the two Au clusters to adjust their atom distances owing to atom misfits among the clusters and the MgO support. Concerning these supported clusters, the obtained results reveal how the cluster size and the interaction affect the structural changes in the interaction between the supported cluster and the MgO support.
关键词:
Cluster;Molecular Dynamics;Computer Simulation;Surface;Nanostructure;molecular-dynamics;mgo(001) surface;au atoms;adsorption;dimers;mgo(100);models;dft
材料科学技术（英文）
Density functional theory was employed to investigate the bismuth segregation at Cu/Cu(3)Sn(010) interface. Five initial constructions were introduced by adopting the adhesion energy criterion. Among them, the so-called "between-Cu" construction in which the interface Cu atoms of Cu slab locate along Cu-Cu bond direction in Cu(3)Sn slab was found to be the most energy-favored at an adhesion energy of 1.96 J/m(2). Based on this construction, five possible segregation sites were examined, and the most likely segregation site was determined with adhesion energy as low as 1.06 J/m(2), which was almost half of the initial one. Comparing with other sites' adhesion energies, it was concluded that size effect took a large part in embrittlement. The analyses of atomic structure and electronic density revealed that the slabs shifted away from interfaces due to bismuth segregation, and the atoms around Bi atom were pressed away. This calculated work agreed qualitatively with reported experimental results.
关键词:
First-principles calculation;Segregation;Bismuth;Interface;SnBi;solder;reactive interface;cu3sn;cu;growth;principles;fracture;crystal;bismuth;joints;copper
赵国升
,
李玉鑫
,
牛思宇
,
刘伟
,
常立民
硅酸盐通报
采用丙三醇-水溶液体系,通过调控前躯体的pH值水热合成了具有{010}晶面择优取向的亚微米级片状BiVO4粉体.通过x射线粉末衍射、紫外-可见光漫反射光谱、扫描电镜、透射电镜和高分辨透射电镜等技术对样品的结构和形貌进行表征.分析表明,丙三醇作为定向指示剂,在pH值为4时,制得了{010}择优取向的纯单斜相BiVO4亚微米片.在模拟太阳光照射下,考察了{010}择优取向单斜BiVO4亚微米片与{121}择优取向单斜BiVO4粉体对亚甲基蓝溶液的光催化活性,结果表明,{010}择优取向单斜BiVO4亚微米片具有更高的光催化活性.
关键词:
{010}晶面
,
择优取向
,
BiVO4
,
光催化
