铁基超导体LaOFeAs,AFe_2As_2(A=Sr,Ca),MFeAs (M=Li,Na),FeSe的晶体结构、磁性及电子结构的第一性原理研究(英文)  

First-principles Study of Lattice,Magnetism and Electronic Structure for Fe-Based Superconductors:LaOFeAs,AFe_2As_2(A=Sr,Ca),MFeAs(M=Li,Na) and FeSe

作　　者：潘敏[1] 冯勇[2] 程翠华[3] 赵勇[1,3] 

机构地区：[1]西南交通大学磁浮技术与磁浮列车教育部重点实验室,四川成都610031 [2]西北有色金属研究院,陕西西安710016 [3]新南威尔士大学,新南威尔士悉尼2052

出　　处：《稀有金属材料与工程》2012年第8期1341-1345,共5页Rare Metal Materials and Engineering

基　　金：the National Natural Science Foundation of China (50588201,50872116);the National High-Tech Research Program of China (2007AA03Z203);the PCSIRT of the Ministry of Education of China (IRT0751);the Innovation Fund for Ph. D. Students of Southwest Jiaotong University (2009);Fundamental Research Funds for the Central Universities (SWJTU09BR154,SWJTU09ZT24);the SRFDP (200806130023,200806130034);the Australian Research Council(DP0559872,DP0881739)

摘　　要：采用密度泛函理论(density functional theory,DFT)中的线性缀加平面波结合增强局域轨道(linearized augmented plane waveand the improved local orbital,APW+lo)的方法研究了新型铁基超导体 LaOFeAs,SrFe2As2, CaFe2As2, LiFeAs,NaFeAs和FeSe的晶体结构、磁性以及电子结构。计算结果表明,铁基超导体的超导电性与该类材料的晶体几何构造以及母体的磁性有密切的关联;超导转变临界温度Tc可以随着FeAs4四面体的畸变程度的减小以及[FeAs]层间距L的增大而提高。进一步对电子结构的研究发现,铁基超导体的磁性主要来自Fe原子的磁矩,pd杂化态决定体系的物理性质,且成为铁基超导体的共有特征。Using density functional theory（DFT） within the scheme of the linearized augmented plane wave and the improved local orbital（APW＋lo）,we investigated the newly discovered FeAs layered compounds LaOFeAs,SrFe2As2,CaFe2As2,LiFeAs,NaFeAs and FeSe.We report the crystal structures,magnetism,and electronic properties of these Fe-based materials.The results reveal a close correlation of the superconductivity of these FeAs superconductors with the lattice geometry formation and magnetism of their parent compounds.The maximal critical temperatures T c could simultaneously increase with the decrease of distortion of the FeAs4 tetrahedrons and the increase of interlayer distance L between two [FeAs] layers.We have further found that the magnetism is mainly attributed to Fe moment,and As4p and Fe3d hybrid states affect the physical natures,which are the common feature in these Fe-pnictide superconductors.

关 键 词：铁基超导体 结构 电子性质 磁性 

分 类 号：TM26[一般工业技术—材料科学与工程]