Ce诱导SrTiO_(3)由非磁绝缘体向铁磁半金属转变的第一性原理研究  

First-principle investigation on Ce doping induced phasetransition from a nonmagnetic insulator to a ferromagnetichalf metal in SrTiO_(3)

作　　者：顾艳妮[1,2] 徐胜[1] 吴小山[2] GU Yanni;XU Sheng;WU Xiaoshan(School of Metallurgy and Materials Engineering,Jiangsu University of Science and Technology,Zhangjiagang 215600,China;School of Physics,Nanjing University,Nanjing 210093,China)

机构地区：[1]江苏科技大学冶金与材料工程学院,张家港215600 [2]南京大学物理学院,南京210093

出　　处：《江苏科技大学学报（自然科学版）》2021年第4期109-113,共5页Journal of Jiangsu University of Science and Technology:Natural Science Edition

基　　金：国家自然科学基金资助项目(51801080)。

摘　　要：通过第一性原理计算采用GGA+U方法,研究了Sr_(1-x) Ce_(x) TiO_(3)(x=0,0.125,0.25)的晶体结构和电磁性质.计算结果表明:Sr_(1-x) Ce_(x) TiO_(3)稳定在立方钙钛矿结构,Ce掺杂导致Sr_(1-x) Ce_(x) TiO_(3)的晶格参数、晶胞体积、Ti-O键长都增大,但Ti-O-Ti键角减小;Sr_(1-x) Ce_(x) TiO_(3)在x=0时为非磁绝缘体,在0.125≤x≤0.25时为铁磁半金属.Ce掺杂导致Sr_(1-x) Ce_(x) TiO_(3)在x=0.125产生非磁绝缘体向铁磁半金属的转变;随着Ce掺杂量增加,Sr_(1-x) Ce_(x) TiO_(3)的金属性和铁磁性加强,很好解释了Sr_(1-x) Ce_(x) TiO_(3)在固体氧化物燃料电池上的应用.这些结果也意味着Sr_(1-x) Ce_(x) TiO_(3)在磁存储器件上具有潜在的应用前景.The crystal structure and electric and magnetic properties of Sr_(1-x) Ce_(x) TiO_(3)(x=0,0.125,0.25)are investigated by first-principle calculations using generalized gradient approximation plus U(GGA+U)method.The results show that Sr_(1-x) Ce_(x) TiO_(3) stabilizes in cubic perovskite structure,and Ce doping results in increase of lattice parameters,cell volume and Ti-O bond length of Sr_(1-x) Ce_(x) TiO_(3),but decrease of Ti-O-Ti bond angle.Sr_(1-x) Ce_(x) TiO_(3) is a non-magnetic insulator at x=0 and a ferromagnetic half metal at 0.125≤x≤0.25.Ce doping induces the phase transition from a nonmagnetic insulator to a ferromagnetic half metal in Sr_(1-x) Ce_(x) TiO_(3) at x=0.125.With the increase of Ce doping,the metallicity and ferromagnetism of Sr_(1-x) Ce_(x) TiO_(3) are strengthened,which explains well the application of Sr_(1-x) Ce_(x) TiO_(3) in solid oxide fuel cell.These results indicate that Sr_(1-x) Ce_(x) TiO_(3) can have important applications in magnetic memory devices.

关 键 词：SrTiO_(3) CE掺杂 非磁-铁磁转变 绝缘体-半金属转变 

分 类 号：O482.4[理学—固体物理] O482.5[理学—物理]