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Photoemission and X-ray Absorption Studies of the Diluted Magnetic Semiconductor Ba $_{1 - y}$ K $_{y}$ (Zn $_{1 - x}$ Mn $_{x}$ ) $_{2}$ As $_{2}$ Isostructural to Fe-based Superconductors

arXiv:1410.2409 · doi:10.1103/PhysRevB.91.140401

Abstract

The electronic and magnetic properties of a new diluted magnetic semiconductor (DMS) Ba $_{1 - x}$ K $_{x}$ (Zn $_{1 - y}$ Mn $_{y}$ ) $_{2}$ As $_{2}$ , which is isostructural to so-called 122-type Fe-based superconductors, are investigated by x-ray absorption spectroscopy (XAS) and resonance photoemission spectroscopy (RPES). Mn $L_{2, 3}$ -edge XAS indicates that the doped Mn atoms have the valence 2+ and strongly hybridize with the $4 p$ orbitals of the tetrahedrally coordinating As ligands. The Mn $3 d$ partial density of states (PDOS) obtained by RPES shows a peak around 4 eV and relatively high between 0-2 eV below the Fermi level ( $E_{F}$ ) with little contribution at $E_{F}$ , similar to that of the archetypal DMS Ga $_{1 - x}$ Mn $_{x}$ As. This energy level creates $d^{5}$ electron configuration with $S = 5/2$ local magnetic moments at the Mn atoms. Hole carriers induced by K substitution for Ba atoms go into the top of the As $4 p$ valence band and are weakly bound to the Mn local spins. The ferromagnetic correlation between the local spins mediated by the hole carriers induces ferromagnetism in Ba $_{1 - x}$ K $_{x}$ (Zn $_{1 - y}$ Mn $_{y}$ ) $_{2}$ As $_{2}$

Photoemission and X-ray Absorption Studies of the Diluted Magnetic Semiconductor Ba1−y​Ky​(Zn1−x​Mnx​)2​As2​ Isostructural to Fe-based Superconductors

Abstract

Photoemission and X-ray Absorption Studies of the Diluted Magnetic Semiconductor Ba $_{1 - y}$ K $_{y}$ (Zn $_{1 - x}$ Mn $_{x}$ ) $_{2}$ As $_{2}$ Isostructural to Fe-based Superconductors