https://doi.org/10.1140/epjb/e2015-50780-7
Regular Article
Reduced iron ordered moment and negative TC-pressure coefficient in iron-arsenide superconductors
Ningbo Institute of Material Technology and Engineering, Chinese
Academy of Sciences, Ningbo
315201, P.R.
China
a e-mail: liugq@nimte.ac.cn
Received:
5
November
2014
Received in final form:
8
January
2015
Published online:
19
March
2015
The striped antiferromagnetic phase of iron-arsenides is investigated by the density functional calculations including Coulomb repulsion. Two low moment solutions with m ≈ 0.4 μB and m ≈ 1.0 μB have been found from calculations. The electronic structures indicate that the low moment states originate in the strong orbital hybridization between antiferromagnetic Fe neighbors. Therefore, the geometry of FeAs4 tetrahedron, which is characterized by a parameter of hAs/a, is crucial to the low moment states. We show that the puzzling negative TC-pressure coefficient of iron-arsenides can be consistently explained by the obtained low moment states.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2015