Experimental probing of exchange interactions between localized spins in the dilute magnetic insulator (Ga,Mn)N
Abstract
The sign, magnitude, and range of the exchange couplings between pairs of Mn ions is determined for (Ga,Mn)N and (Ga,Mn)N:Si with x < 3%. The samples have been grown by metalorganic vapor phase epitaxy and characterized by secondary-ion mass spectroscopy; high-resolution transmission electron microscopy with capabilities allowing for chemical analysis, including the annular dark-field mode and electron energy loss spectroscopy; high-resolution and synchrotron x-ray diffraction; synchrotron extended x-ray absorption fine-structure; synchrotron x-ray absorption near-edge structure; infra-red optics and electron spin resonance. The results of high resolution magnetic measurements and their quantitative interpretation have allowed to verify a series of ab initio predictions on the possibility of ferromagnetism in dilute magnetic insulators and to demonstrate that the interaction changes from ferromagnetic to antiferromagnetic when the charge state of the Mn ions is reduced from 3+ to 2+.
Keywords
Cite
@article{arxiv.1008.2083,
title = {Experimental probing of exchange interactions between localized spins in the dilute magnetic insulator (Ga,Mn)N},
author = {A. Bonanni and M. Sawicki and T. Devillers and W. Stefanowicz and B. Faina and Tian Li and T. E. Winkler and D. Sztenkiel and A. Navarro-Quezada and M. Rovezzi and R. Jakiela and A. Grois and M. Wegscheider and W. Jantsch and J. Suffczynski and F. D'Acapito and A. Meingast and G. Kothleitner and T. Dietl},
journal= {arXiv preprint arXiv:1008.2083},
year = {2012}
}
Comments
12 pages, 14 figures; This version contains the detailed characterization of the crystal structure as well as of the Mn distribution and charge state