Electronic structure and magnetism of K-intercalated iron chalcogenides
2015 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 92, no 10, 104421Article in journal (Refereed) Published
We theoretically investigate the electronic and magnetic structure of vacancy bearing K-intercalated Fe chalcogenides (Ch = Se and Te) using first-principles calculations. Motivated by experimental report on the compositions and suggested Fe valences of the parent insulating and superconducting phases on vacancy bearing K-intercalated Fe selenides, we consider three compositions, KFe(1.5)Ch(2), K(0.94)Fe(1.5)Ch(2), and KFe(1.56)Ch(2). The electronic structure calculated on geometry optimized crystal structure of KFe1.56Se2 is found to be markedly different from the other two compositions due to formation of the ferromagnetic one-dimensional chain of Fe atoms in the case of KFe1.56Se2 as opposed to trimer geometry of Fe atoms in KFe1.5Se2 and K0.94Fe1.5Se2. This is expected to have an important bearing on the composition specific observation of superconducting properties in vacancy bearing K-intercalated Fe selenides. Interestingly, the Te compounds, which are yet to be synthesized, show very similar magnetic properties as in Se compounds, in marked contrast to 11 compounds, FeSe and FeTe. This hints that unlike FeTe, vacancy bearing K-intercalated Fe tellurides may be potential candidates for exploring superconductivity.
Place, publisher, year, edition, pages
2015. Vol. 92, no 10, 104421
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-264624DOI: 10.1103/PhysRevB.92.104421ISI: 000361369700002OAI: oai:DiVA.org:uu-264624DiVA: diva2:864686