Mn3delectronic configurations in(Ga1−xMnx)

Abstract

We applied x-ray absorption spectroscopy and x-ray magnetic circular dichroism ͑XMCD͒ at the Mn 2p-3d resonances to study the Mn 3d electronic configuration and the coupling of Mn 3d magnetic moments in various Ga 1−x Mn x As films. The homogeneity of the Mn depth profile throughout the Ga 1−x Mn x As film was tested by additional structure-sensitive x-ray resonant reflectivity measurements. In all investigated Ga 1−x Mn x As films the electronic and magnetic configuration of the Mn impurities varies throughout the Mn-doped layer. This inhomogeneity is caused by the surface segregation of nonferromagnetic Mn in a d 5 configuration. X-ray resonant reflectivity data show that the accumulation of nonferromagnetic Mn near the surface is strongly enhanced by low-temperature annealing. By XMCD we identified the Mn species responsible for the long-range ferromagnetic coupling. It is characterized by an Mn 3d 5 -3d 6 mixed-valence acceptor state that is unchanged at all investigated Mn concentrations, ranging from 1% to 6%. Additional nonferromagnetic Mn occurs in the bulk of high-concentration samples. We discuss a model in which the latter is due to antiferromagnetic Mn-Mn nearest-neighbor pairs.

Moment evolution across the ferromagnetic phase transition of giant magnetocaloric(Mn,Fe)2(P,Si,B)Yibole1, Guillou2, Caron3 et al. 2015Phys. Rev. B28372View full textAdd to dashboardCite

“…Besides, the small nonzero value also indicates that Mn and Fe are not in a pure 3d 5 and 3d 6 ground state configuration, but have a small admixtures of 3d 6 for Mn and 3d 7 for Fe due to the hybridization with neighbouring atoms. 51,52 Though both the Mn and Fe atoms have a very small orbital magnetic moment, it is interesting to note that µ orb for Fe is one order of magnitude higher than for Mn.…”

Identifying the character of ferromagnetic Mn in epitaxial Fe/(Ga,Mn)As heterostructures

“…[19][20][21][22] A recent detailed study on the depth concentration of Mn in ͑Ga,Mn͒As reveals the presence of Mn with d 5 configuration up to 6 nm from the interface, coexisting with Mn Ga and not related to oxide. 23 Results in Fig. 1, obtained on controlled epitaxial systems with negligible oxide contribution indicate a surface-interface region with d 5 -like character ͑TEY spectrum͒ and a bulk region, mainly representative of the Mn Ga ͑PY spectrum͒.…”

Photoemission of Ga1–xMnx As with high Curie temperature and transformation into MnAs of zincblende structure

“…Another confirmation is through the magnetic field-dependence of XMCD where Mn interstitials are identified by their shift (by ~0.5 eV) to higher energy and their deviating field dependence [21]. The surface segregation of interstitial Mn has also been confirmed by depth profiling using X-ray resonant reflectivity [22] and core-level photoelectron spectroscopy at high kinetic energy of 4.5 keV with increased probing depth [23]. Resonant photoemission at the Mn L-edge with higher probing depth than at the M-edge and stronger Mn enhancement (~×20) was used to clarify the Mn density of states in the subsurface region [19].…”