Doping Dependent Changes in Nitrogen 2$p$ States in the Diluted Magnetic Semiconductor Ga${}_{1-x}$Cr${}_x$N

Abstract

We study the electronic structure of the recently discovered diluted magnetic semiconductor Ga${}_{1-x}$Cr${}_x$N ($x$ = 0.01-0.10). A systematic study of the changes in the $occupied$ and $unoccupied$ ligand (N) partial density of states (DOS) of the host lattice is carried out using N 1$s$ soft x-ray emission and absorption spectroscopy, respectively. X-ray absorption measurements confirm the wurtzite N 2$p$ DOS and substitutional doping of Cr into Ga-sites. Coupled changes in the $occupied$ and $unoccupied$ N 2$p$ character DOS of Ga${}_{1-x}$Cr${}_x$N identify states responsible for ferromagnetism consistent with band structure calculations.

5 pages, 4 figures, submitted to Phys. Rev. B