We present a density functional study of SrCu4As2 and KCu4As2. The two isostructural compounds constitute a system that allows a broad range of doping of CuAs layers through nominally K+ for Sr2+ substitution. SrCu4As2 (space group R3̄m) is a metal having highly dispersive bands at E F, two holelike Fermi sheets in the form of corrugated cylinders along Γ-Z and electron pockets around F points in the rhombohedral Brillouin zone. Cu 3d states are located at 2.5 eV below EF, giving little contribution to the bands near EF. The F-point electron pockets disappear in KCu4As2 and the compound exhibits a large multisheet two-dimensional Fermi surface with a somewhat enhanced d character through Cu 3d-As 4p bonding. Despite shifting EF toward the Cu 3d bands in KCu4As2, the compound remains with completely populated d shells and it is unlikely to exhibit superconductivity of a type similar to that in the ternary iron arsenides.
|期刊||Physical Review B - Condensed Matter and Materials Physics|
|出版狀態||Published - 2011 八月 19|
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