Magnetic Properties and Electronic Configurations of Mn Ions in the Diluted Magnetic Semiconductor Ba1−xKx(Zn1−yMny)2As2 Studied by X-ray Magnetic Circular Dichroism and Resonant Inelastic X-ray Scattering

The magnetic properties and the electronic excitations of the new diluted magnetic semiconductor Ba_1−xK_x(Zn_1−yMn_y)₂As₂ have been studied by x-ray magnetic circular dichroism (XMCD) and resonant inelastic x-ray scattering (RIXS) at the Mn L_2,3 edge. The sum rule analysis of the XMCD spectra yields the net spin moment of 0.45 μ_B/Mn and the small orbital moment of 0.05 μ_B/Mn. This indicates that the Mn atoms are in the high-spin configurations of d⁵, whereas the presence of competing ferromagnetic and antiferromagnetic interactions between the Mn ions reduces the net spin moment. RIXS spectra show broad peaks from 1 to 6 eV energy loss, which originate from the d–d crystal field excitations of the Mn ions. Based on a comparison of the RIXS line shapes with those of Ga_1−xMn_xAs, we conclude that the ground state of Mn in Ba_1−xK_x(Zn_1−yMn_y)₂As₂ consists not only of the charge-transferred 3d⁵L electron configuration (L: ligand hole) with weakly bound holes as in Ga_1−xMn_xAs, but also of the pure 3d⁵ configuration with free holes.