Article ID Journal Published Year Pages File Type
1593620 Solid State Communications 2011 4 Pages PDF
Abstract

The crystal structure, magnetism properties, and density of states for FeAs layered compound SrFe2As2 have been investigated by using the density functional theory (DFT) method. The magnetism under a checkerboard nearest neighbor anti-ferromagnetic (NN AFM) and ferromagnetic (FM) order ground-state have been analyzed with substitution for Sr with K ion in Sr1−xKxFe2As2. The results indicate that the distortion of FeAs tetrahedrons is sensitive to the electron doping concentration. The system magnetism was suppressed by K doping in NN-AFM ground state instead of FM. The density of states at Fermi level N(EF)N(EF) under NN AFM ground state would be regarded as a driving force for the increased TcTc of Sr1−xKxFe2As2 system as observed experimentally. Our calculation reflects that NN AFM type spin fluctuation may still exist in the Sr1−xKxFe2As2 system and it may be an origin of strong spin fluctuation in this system besides the spin density wave (SDW) states.

► FeAs4 tetrahedrons of Sr1−xKxFe2As2 are sensitive to the electron doping. ► Magnetism was suppressed in the NN-AFM state of Sr1−xKxFe2As2 system. ►N(EF)N(EF) under NN AFM was regarded as a driving force for the increased TcTc. ► NN AFM type spin fluctuation may still exist in Sr1−xKxFe2As2 system.

Related Topics
Physical Sciences and Engineering Materials Science Materials Science (General)
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