X-ray absorption spectroscopy in Mnx Ge1-x diluted magnetic semiconductor: Experiment and theory

Accurate first-principles calculations of soft x-ray absorption spectra are compared with experimental data obtained for the ion-implanted Mnx Ge1-x ferromagnetic semiconductor. The well-defined features in the spectra are recognized as a signature of homogeneous Mn dilution within the Ge host, as demonstrated by comparing the Mn spectra in diluted MnGe alloys with other competing Mn-Ge crystalline phases. Moreover, provided that an efficient Mn dilution is achieved, the nature of the semiconducting host is shown to affect only slightly the Mn absorption spectrum, as shown by the similarity of the present results with those for other magnetic semiconductors. Both these findings establish the relevance of ion-implantation in the dilute magnetic semiconductor framework, emphasizing its potential impact in device technology.