原子级模拟在四方SrTiO₃畴壁能计算中的应用

原子级模拟在四方SrTiO 3 畴壁能计算中的应用 APPLICATION OF ATOMISTIC SIMULATION IN ENERGY CALCULATION OF DOMAIN BOUNDARIES IN TETRAGONAL SrTiO 3 刘蕾 Liu Lei 1 first-author 王仁卉 Wang Renhui 1 武汉大学物理学系 武汉大学物理学系 Department of Physics, Wuhan University Department of Physics, Wuhan University 利用原子级计算机模拟对四方ＳｒＴｉＯ３中畴壁能进行了研究．在经典Ｂｏｒｎ模型基础上用来描述离子晶体的原子级模拟，其能量表达式由长程库仑势和短程排斥势构成．后者为一含参数表达式，式中参数可由晶体的晶格常数、晶体结构和弹性常数等实验数据拟合得出．四方ＳｒＴｉＯ３由高温立方ＳｒＴｉＯ３相变而来，应存在反相畴界、孪晶界和平移孪晶界等３种畴界．本文用原子级模拟的技术对这３种畴界能进行了计算．结果表明畴界能尤其是反相畴界能非常小． In this work the domain boundary energies in tetragonal SrTiO 3 are studied by atomistic computer simulation technique. The atomistic simulation is based on the classical Born model in which the lattice energy is the sum of firstly long range Coulombic interactions and secondly short range repulsive interactions. The second form is described by adjustable parameters which can be fitted by lattice parameters, crystal structure and elastic constants. Tetragonal SrTiO 3 is transformed from high temperature cubic SrTiO 3, hence there should be three orientation domains V x, V y and V z whose C directions are parallel to the cubic , and directions respectively and anti phase domains in each orientation domain. This work studied the energies of anti phase domain, twin and translation twin boundaries. The results reveal very low domain boundary energies for tetragonal SrTiO 3, especially for the anti phase domain boundary. 原子级模级 四方SrTiO3 畴界能 atomistic simulation tetragonal SrTiO 3 domain boundary energy O723.5 1998-03-01 2021-04-01 3