The electronic structure of the new diluted magnetic semiconductor Ba1-xKx(Zn1-yMny)2As2 (x=0.30, y=0.15) in single crystal form has been investigated by angle-resolved photoemission spectroscopy (ARPES). Measurements with soft x rays clarify the host valence-band electronic structure primarily composed of the As 4p states. Two hole pockets around the Γ point, a hole corrugated cylinder surrounding the Γ and Z points, and an electron pocket around the Z point are observed, and explain the metallic transport of Ba1-xKx(Zn1-yMny)2As2. This is contrasted with Ga1-xMnxAs (GaMnAs), where it is located above the As 4p valence-band maximum (VBM) and no Fermi surfaces have been clearly identified. Resonance soft x-ray ARPES measurements reveal a nondispersive (Kondo-resonance-like) Mn 3d impurity band near the Fermi level, as in the case of GaMnAs. However, the impurity band is located well below the VBM, unlike the impurity band in GaMnAs, which is located around and above the VBM. We conclude that, while the strong hybridization between the Mn 3d and the As 4p orbitals plays an important role in creating the impurity band and inducing high temperature ferromagnetism in both systems, the metallic transport may predominantly occur in the host valence band in Ba1-xKx(Zn1-yMny)2As2 and in the impurity band in GaMnAs.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 2015 Dec 10