摘要
在激光分子束外延(LMBE)生长SrTiO3(STO)薄膜过程中,激光闪蒸出的Sr,Ti,O原子的微观反应过程及粒子形态是STO薄膜生长初期形成的关键.采用密度泛函理论中的广义梯度近似(DFT/GGA)方法,在PW91/DNP水平上研究了Sr,Ti,O原子在真空中的优先反应过程和形态,计算研究了SrO,TiO2和STO分子形成的反应机理,获得了相应的中间体和过渡态及反应活化能,并运用前线轨道理论分析了STO分子的形成机理.对比计算了STO分子可能的几何构型,得到了比较稳定的构型,其几何特征与STO单胞部分相似.计算研究表明,SrO,TiO2,STO分子是LMBE外延生长STO薄膜初期的主要粒子形态.
It is very important to learn the microscopic reaction and particle states of Sr,Ti, O atoms which are evaporated by laser molecular beam epitaxy in the early growth of SrTiO3 thin films. The preferential reaction processes of Sr, Ti, O atoms were investigated by generalized gradient approximation of density functional theory at the PW91/DNP level. The reaction mechanisms of SrO,TiO2 and SrTiO3 molecules were calculated and analyzed by highest occupied and lowest unoccupied molecular orbital theory, and several possible configurations of SrTiO3 molecules were calculated. We obtained stable configurations of SrTiO3 molecule, of which the geometric eigcnvalue is similar with the SrTiO3 unit cell. These results indicate that the SrO, TiO2 and SrTiO3 molecules are the primary particle states in the early growth of SrTiO3 thin film.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第4期2340-2346,共7页
Acta Physica Sinica
基金
国防预研基金(批准号:51310Z03,61363)
四川省青年科技基金(批准号:07ZQ026-021)资助的课题~~
关键词
SRTIO3薄膜
反应机理
活化能
SrTiO3 thin films, reaction mechanism, activation energy
