Interplay between localization and magnetism in (Ga,Mn)As and (In,Mn)As

Abstract

Ion implantation of Mn combined with pulsed laser melting is employed to obtain two representative compounds of dilute ferromagnetic semiconductors (DFSs): Ga1-xMnxAs and In1-xMnxAs. In contrast to films deposited by the widely used molecular beam epitaxy, neither Mn interstitials nor As antisites are present in samples prepared by the method employed here. Under these conditions the influence of localization on the hole-mediated ferromagnetism is examined in two DFSs with a differing strength of p-d coupling. On the insulating side of the transition, ferromagnetic signatures persist to higher temperatures in In1-xMnxAs compared to Ga1-xMnxAs with the same Mn concentration x. This substantiates theoretical suggestions that stronger p-d coupling results in an enhanced contribution to localization, which reduces hole-mediated ferromagnetism. Furthermore, the findings support strongly the heterogeneous model of electronic states at the localization boundary and point to the crucial role of weakly localized holes in mediating efficient spin-spin interactions even on the insulator side of the metal-insulator transition.

23 pages, 10 figures, to appear at Phys. Rev. Mater

References in corpus (10)

• Achieving High Curie Temperature in (Ga,Mn)As
• Interplay between carrier localization and magnetism in diluted magnetic and ferromagnetic semiconductors
• Hole states in wide band-gap diluted magnetic semiconductors and oxides
• Onset of ferromagnetism in low-doped GaMnAs
• Antisite effect on ferromagnetism in (Ga,Mn)As
• Metal-insulator transition by isovalent anion substitution in Ga1-xMnxAs: Implications to ferromagnetism
• Electrical transport and ferromagnetism in Ga1-xMnxAs synthesized by ion implantation and pulsed-laser melting
• High Curie temperature and perpendicular magnetic anisotropy in homoepitaxial InMnAs films
• Electronic structure of (Ga,Mn)As revisited
• Ferromagnetic InMnAs on InAs Prepared by Ion Implantation and Pulsed Laser Annealing

Cited by in corpus (4)

• Enhanced ferromagnetism in cylindrically confined MnAs nanocrystals embedded in wurtzite GaAs nanowire shells
• Phase diagram of a ferromagnetic semiconductor. The origin of superparamagnetism
• Exchange interaction for Mn acceptor in GaAs: revealing its strong deformation dependence
• Hole compensation effect in III-Mn-V dilute ferromagnetic semiconductors