(1. 昆明理工大學 真空冶金國家工程實驗室，昆明 650093；
2. 云南省有色金屬真空冶金重點實驗室，昆明 650093)
摘 要: 利用密度泛函理論計算砷化鎵(GaAs)的能帶結(jié)構(gòu)、態(tài)密度、密立根布居和差分電荷密度等參數(shù)，對其熱分解過程進行分子動力學模擬。計算模擬結(jié)果表明：在動力學模擬條件下，部分Ga—As 鍵發(fā)生斷裂，生成Ga和As2，Ga—As 鍵隨模擬時間的延長分步斷裂。同時，以GaAs 廢料為原料，對其進行真空熱分解實驗研究，主要考察蒸餾溫度和恒溫時間對Ga 和As 分離效果的影響。實驗結(jié)果表明：當系統(tǒng)壓力為3~8 Pa、溫度為1273 K和恒溫時間為3 h 時，殘留物鎵的品質(zhì)較好，純度高于99.99%，砷主要以單質(zhì)形態(tài)存在，危害小。計算模擬結(jié)果與理論分析和實驗結(jié)果吻合較好。
關(guān)鍵字: GaAs；鎵；真空熱分解；動力學模擬
（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
