钼酸镉晶体本征点缺陷的计算机模拟计算

Computer Simulating Calculation of Intrinsic Defects in CdMoO_4 Crystal

本文利用GULP计算软件拟合了CdMoO4晶体势参数,在此基础上研究了该晶体的本征点缺陷,计算了本征点缺陷的生成能。结果表明,在CdMoO4晶体生长过程中,孤立缺陷主要以肖特基缺陷的形式(V2+O和V2-Cd)存在。晶体中氧的夫伦克儿缺陷具有较低的生成能,是CdMoO4晶体的主要缺陷类型。Cd的夫伦克儿缺陷在高温条件下将起重要作用,由氧空位引起的F心和F+心与700 nm吸收带的形成有关。

The potential parameter of CdMoO4 was fitted by GULP（ General Utility Lattice Program）, and intrinsic defects were investigated based on the simulation. The formation energies of intrinsic defects were also calculated. The results indicate that most isolated defects in the as-grown CdMoO4 crystal exist in the form of the Schottky-type （ Vo^2＋ and Vcd^2- ）. Oxygen Frenkel defects in crystal have lower formation energy so they should be main defects in the crystal . The Frenkel defects of Cd will play significant role at high temperature. The formation of the absorption band peaking at 700 nm is related to F and F^＋ colour centers caused by the oxygen vacancy Vo^2＋.