摘要
通过Ca替换CaCu_3Ti_4O_(12)晶胞中的所有Cu,建立了包含TiO6八面体扭转的CaTiO3;通过Cu替换CaTiO32×2×2超胞中3/4的Ca,建立了不包含CuO_4正方形的CaCu_3Ti_4O_(12)。采用Materials Studio软件的CASTEP模块,对比了上述晶体和标准晶体成键状况、能带结构、态密度及介电函数,分析了TiO6八面体扭转和CuO_4正方形的影响,发现了Cu-O键或CuO_4正方形对CaCu_3Ti_4O_(12)光频介电常数的关键性作用。研究结果提供了通过内禀机制优化CaCu_3Ti_4O_(12)材料介电性能的新途径。
In order tOreveal the influence of twisted TiO6 octahedrons and CuO4 squares on dielectric properties of CaCu3Ti4O12,CaTiO3 and CaCu3Ti4O12 were investigated comparatively by First principles.Based on the crystal cell of CaCu3Ti4O12,CaTiO3 crystal cell with twisted TiO6 octahedrons was built by substituting Ca for all the Cu atoms.Based on 2×2×2 supercell of CaTiO3,CaCu3Ti4O12 crystal cell without CuO4 squares was built by substituting Cu for 3/4 of the Ca atoms.CASTEP module in First principle calculation software of Materials StudiOwas used tOinvestigate the difference in bonding,energy band structure,state density and dielectric function for the crystals mentioned above and normal CaTiO3 and CaCu3Ti4O12 crystals.The influence of twisted TiO6 octahedrons and CuO4 squares for perovskite was analyzed.It was found that Cu-Obonds or CuO4 squares play a key role in optical frequency dielectric permittivity of CaCu3Ti4O12.The research of this paper offers a new route tOoptimize dielectric properties of CaCu3Ti4O12 by intrinsic mechanism.
作者
成鹏飞
宋江
曹壮
CHENG Pengfei;SONG Jiang;CAO Zhuang(School of Science,Xi’an Polytechnic University,Xi’an 710048)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2017年第A01期149-153,163,共6页
Materials Reports
基金
国家自然科学基金(51277138)
陕西省教育厅科研专项(12JK0434
2010JK573)
西安工程大学博士科研启动基金(BS0814)
西安工程大学研究生创新基金(CX201616)
