【摘要】 对具有钙钛矿结构的钛酸钡(BT)、钛酸铅(PT)、锆酸铅(PZ)、三种钛/锆比例的锆钛酸铅(PZT)和镁铌酸铅(PMN)的部分构型建立了复晶胞模型,并运用从头算分子动力学方法CPMD对其极化性能进行了模拟.计算结果表明自发极化强度与B格点原子类型和其偏离所处氧笼中心距离有关;d33/χe最大值:25%/75%(Ti/Zr)的PZT的出现在(111)方向,其它晶体均出现在(001)方向;PZ,PZT,PMN的d33/χe值较高;g33×χe最大值出现在(001)或(110)方向;PT和PZT的g33×χe值较大.更多还原

【Abstract】 Perovskite distortion models of supercell (2×2×2) were set up for BaTiO3, PbTiO3, PbZrO3, and three selected alloys of PbZrO3-PbTiO3, and (2×2×3) for PbMg1/3Nb2/3O3. Ab initio molecular dy- namics simulations were performed for understanding their polarization and piezoelectricity. Spontaneous polarization P* of alloys was determined by the atom B and its distortion away from the center of oxygen cage: P* = ∑ B % PB 0 Δ RB /ΔRB0.更多还原