Ferromagnetism of wide-bandgap semiconductor surfaces: Mg-doped AlN

Abstract

The surface magnetism of Mg-doped AlN is investigated by the first-principles method. All studied surfaces, whether they are non-polar, polar or semi-polar, favor a ferromagnetic ground state, which is stabilized by the virtual charge hopping between partially filled states of MgN clusters. However, the stability of ferromagnetism varies from surface to surface owing to the interplay among the localization of magnetic moments, energy level splitting, and sp–p interaction between MgN clusters. Among the various surfaces being studied, the Mg-doped AlN surface is expected to be ferromagnetic at room temperature as a result of its strong localization of defect states.

First-principles study of d0 ferromagnetism in alkali-metal doped GaN

“…In 2002, magnetism induced by vacancies was first investigated in CaO, 5) and then considerable work have been devote to the study of ferromagnetic semiconductors without TM elements. [6][7][8] Recently, room temperature ferromagnetism in Li-doped ZnO has been observed in experiment. 9,10) This type of "d 0 ferromagnetism" provide a new way to search room-temperature ferromagnetic semiconductors, as well as a challenge to understand the origin of the magnetism.…”