(1. 昆明理工大学 真空冶金国家工程实验室，昆明 650093；
2. 云南省有色金属真空冶金重点实验室，昆明 650093)
摘 要: 利用密度泛函理论计算砷化镓(GaAs)的能带结构、态密度、密立根布居和差分电荷密度等参数，对其热分解过程进行分子动力学模拟。计算模拟结果表明：在动力学模拟条件下，部分Ga—As 键发生断裂，生成Ga和As2，Ga—As 键随模拟时间的延长分步断裂。同时，以GaAs 废料为原料，对其进行真空热分解实验研究，主要考察蒸馏温度和恒温时间对Ga 和As 分离效果的影响。实验结果表明：当系统压力为3~8 Pa、温度为1273 K和恒温时间为3 h 时，残留物镓的品质较好，纯度高于99.99%，砷主要以单质形态存在，危害小。计算模拟结果与理论分析和实验结果吻合较好。
关键字: GaAs；镓；真空热分解；动力学模拟
（1. National Engineering Laboratory for Vacuum Metallurgy,
Kunming University of Science and Technology,Kunming 650093,China;
2. Key Laboratory of Vacuum Metallurgy for Nonferrous Metals of Yunnan Province,Kunming 650093,China）
Abstract:The theoretical calculation of energy band structure,density of states,Mulliken overlap population and electron density difference of GaAs was carried out by density functional theory (DFT). The dynamics simulations of GaAs about the process of thermal decomposition were performed. The calculated results show that a part of Ga—As bonds are broken,and Ga and As2 are produced. Ga—As bonds are broken step by step with prolonging time. Meanwhile,the thermal decomposition experiment was carried out by using GaAs scraps as raw material. The effects of distillation temperature and distillation time on the separation of Ga and As were investigated. The experiment results show that the metallic gallium obtained is good and the content of which is larger than 99.99% at 1273 K for 3 h when the system pressure is 3-8 Pa. And arsenic obtained exists in the form of simple substance which has little damage. The calculated results are in good agreement with the theoretical analysis and experiment results.
Key words: GaAs; gallium; thermal decomposition under vacuum; dynamics simulation
