First-Principles Calculations of the Electronic Structure of Tetragonalα-FeTe andα-FeSe Crystals: Evidence for a Bicollinear Antiferromagnetic Order

Fengjie Ma, Wei Ji, Jiangping Hu, Zhong-Yi Lu, Tao Xiang
2009 Physical Review Letters  
By the first-principles electronic structure calculations, we find that the ground state of PbO-type tetragonal α-FeTe is in a bi-collinear antiferromagnetic state, in which the Fe local moments (∼2.5μ_B) are ordered ferromagnetically along a diagonal direction and antiferromagnetically along the other diagonal direction on the Fe square lattice. This bi-collinear order results from the interplay among the nearest, next nearest, and next next nearest neighbor superexchange interactions J_1,
more » ... and J_3, mediated by Te 5p-band. In contrast, the ground state of α-FeSe is in the collinear antiferromagnetic order, similar as in LaFeAsO and BaFe_2As_2.
doi:10.1103/physrevlett.102.177003 pmid:19518816 fatcat:tncdrugpmffo7b4zgrdbvgooje