Pre-edge XANES structure of Mn in (Ga,Mn)As from first principles
Chem.
Met. Alloys 2
(2009) 34-38
https://doi.org/10.30970/cma2.0085
Nataliya A. GONCHARUK, Jan KUČERA, Ludvík SMRČKA
The X-ray absorption near-edge structure
(XANES) at the Mn K-edge in the (Ga,Mn)As magnetic semiconductor
was simulated using the full potential linearized
augmented plane wave (FLAPW) method including the core-hole effect. The
calculations were performed in the supercell scheme
for a substitutional and two tetrahedral interstitial
Mn sites. The resulting pre-edge absorption
structures show sharp distinction between the spectra simulated for the substitutional and interstitial Mn
defects, which is determined mainly by the second nearest neighbor ligands. A single feature is obtained for the substitutional Mn impurity,
whereas two peaks appear for both types of interstitial defects. An
interpretation of the pre-edge features is proposed.
Normalized ab-initio Mn K-edge XANES spectra simulated including the core-hole
effect in the 64-atom (Ga,Mn)As
supercell for three different Mn
sites in the substitutional (MnGasub)
and two tetrahedral interstition positions (MnAsint and MnGaint).
Energies of spectra are shifted by the experimental transition energy of a Mn atom, Eo = 6539 eV. The grey region indicates the pre-edge part of
absorption spectra (peaks A and B), which is shown in detail in the
insert.
Keywords
(Ga,Mn)As
magnetic semiconductor / X-ray absorption near-edge structure / Substitutional / Interstitial / Defects