Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 46: Poster 2
HL 46.58: Poster
Donnerstag, 29. März 2007, 15:00–17:30, Poster A
Magnetic properties of ZnMnO — •Jan Stehr1, Christoph Knies1, Detlev Hoffman1, Wei Xu2, Yingxue Zhou2, and Xinyi Zhang2 — 1I. Physikalisches Institut, Justus-Liebig-Universität, Heinrich-Buff-Ring 16, D- 35392 Giessen — 2Department of Physics, Fudan University, 220 Handan Road, Shanghai 200433, China
A set of ZnMnO samples grown by MBE on Si with Mn concentrations from 3 % to 30% has been investigated by extended x-ray absorption fine structure (EXAFS) measurements, electron paramagnetic resonance (EPR) and magnetisation measurements. The magnetisation shows a ferromagnetic like hysteresis in samples with Mn concentrations below 10 %. An estimate of the ratio of the net magnetisation to the concentration of saturated magnetisation Mn2+ spins gives only 2 % of the total Mn content. The EPR shows dominating signals originating from concentration broadened, and exchange narrowed Mn2+ ions. The formation of secondary Mn phases is evident from EXAFS for samples with Mn concentrations higher than 20 %.