The electronic and magnetic properties of a new diluted magnetic semiconductor (DMS) Ba1-xKx(Zn1-yMny)2As2, 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 L2,3-edge XAS indicates that the doped Mn atoms have a valence 2+ and strongly hybridize with the 4p orbitals of the tetrahedrally coordinating As ligands. The Mn 3d partial density of states obtained by RPES shows a peak around 4 eV and is relatively high between 0 and 2 eV below the Fermi level (EF) with little contribution at EF, similar to that of the archetypal DMS Ga1-xMnxAs. This energy level creates a d5 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 4p 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 Ba1-xKx(Zn1-yMny)2As2.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 2015 Apr 6