We report on the carrier-induced ferromagnetism in Ge(Mn,Fe) magnetic semiconductor insulating-type thin-film structures prepared using sequential deposition at Tg =520 K with subsequent annealing at Tg. In the resulting films Mn and Fe are diffused in the Ge matrix without compromising the epitaxial structure. The anomalous Hall effect serves as a manifestation of the carrier-induced magnetism, with p -type conductivity and the Curie temperature TC =209 K. The additional doping with Fe stabilizes epitaxial growth and carrier-mediated magnetism at levels of magnetic doping exceeding 10%. We conclude that indirect ferromagnetic exchange is mediated by localized holes with concentration n∼ 1020 cm-3 and mobility μ∼10 cm2 (V s).
|Journal||Applied Physics Letters|
|State||Published - 29 May 2006|