Author/Authors :
Przybyli?ska، نويسنده , , H. and Bonanni، نويسنده , , A. and Wolos، نويسنده , , A. and Kiecana، نويسنده , , M. and Sawicki، نويسنده , , Michelle M. and Dietl، نويسنده , , T. and Malissa، نويسنده , , H. and Simbrunner، نويسنده , , C. and Wegscheider، نويسنده , , M. and Sitter، نويسنده , , H. and Rumpf، نويسنده , , K. and Granitzer، نويسنده , , P. and Krenn، نويسنده , , H. and Jantsch، نويسنده , , W.، نويسنده ,
Abstract :
We report on metal-organic chemical vapour deposition growth of GaN:Fe and its characterization by means of high-resolution X-ray diffraction, secondary ion mass spectroscopy, electron spin resonance, and magnetization measurements. Electron spin resonance studies demonstrate the existence of Fe in the isolated 3d5 (Fe3+) state. Magnetic measurements reveal, apart from Curie paramagnetism due to Fe3+, a temperature independent contribution which we attribute tentatively to van Vleck paramagnetism of Fe in the 2+ state. We conclude that the Fe ions coexist in two charge states in the investigated samples. The fraction of Fe3+ ions was found to increase upon additional co-doping with Mg acceptors, both in ESR as well as in magnetization measurements.
