纤锌矿Be_(1-x)Mg_xO合金的电子结构和相特性研究  

Study on the electronic structures andphase properties of wurtzite Be_(1-x)Mg_xO alloy

作　　者：郑树文[1] 张涛[1] 张力[1] 陈振世 

机构地区：[1]华南师范大学光电子材料与技术研究所广东省光电功能材料与器件工程技术研究中心,广州510631

出　　处：《功能材料》2016年第3期146-150,157,共6页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(61176043);广东省科技计划资助项目(2015B090903078);华南师范大学青年教师培育基金资助项目(2012KJ018)

摘　　要：采用第一性原理的平面波超软赝势方法,对纤锌矿Be_(1-x)Mg_xO合金的电子结构和相特性进行研究。结果显示,纤锌矿Be_(1-x)Mg_xO的能隙由价带顶O2p态和导带底Mg3s态共同决定。随着Mg组分的增大,Be_(1-x)Mg_xO合金的能隙逐渐变小,合金离子性在增强。Be—O和Mg—O的平均键长差距大致使Be_(1-x)Mg_xO合金内部产生明显的晶格振动效应,而无序相Be_(1-x)Mg_xO合金的形成能比有序相要低,容易使纤锌矿Be_(1-x)Mg_xO合金内部产生无序结构,因此制备纤锌矿Be_(1-x)Mg_xO合金时要适当提高实验温度。The electronic structures and phase properties of wurtzite(w)Be_(1-x)Mg_xO alloy are investigated by the first-principles method based on the density functional theory.The calculated results show that the bandgap of w-Be_(1-x)Mg_xO is determined by O2 p and Mg3 sstates.The bandgap of Be_(1-x)Mg_xO alloy becomes smaller and its ionic character is enhanced with the Mg content xof Be_(1-x)Mg_xO is increased.There is a strong lattice vibration effect in the w-Be1-x MgxO structure,which chiefly originates from the large difference in the average bond length between Be—O and Mg—O.w-Be_(1-x)Mg_xO alloy is likely to form disordered structure because the formation energy of its disordered phase is lower than its ordered phase,so it is necessary to prepared the w-Be1-x MgxO alloy with higher growth temperature.

关 键 词：第一性原理 电子结构 相特性 Be1-xMgxO 

分 类 号：O469[理学—凝聚态物理] O471[理学—电子物理学]