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Synthesis, characterization and modeling of high quality ferromagnetic Cr-doped AlN thin films

Stephen Y. Wu·H. X. Liu·Lin Gu·R. K. Singh·L. Budd·M. van Schilfgaarde·M. R. McCartney·David J. Smith·N. Newman
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Abstract

We report a theoretical and experimental investigation of Cr-doped AlN. Density functional calculations predict that the isolated Cr t2 defect level in AlN is 1/3 full, falls approximately at midgap, and broadens into an impurity band for concentrations over 5%. Substitutional Al1-xCrxN random alloys with 0.05 <= x <= 0.15 are predicted to have Curie temperatures over 600 K. Experimentally, we have characterized and optimized the molecular beam epitaxy thin film growth process, and observed room temperature ferromagnetism with a coercive field, Hc, of 120 Oersted. The measured magnetic susceptibility indicates that over 33% of the Cr is magnetically active at room temperature and 40% at low temperature.

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Stephen Y. Wu, H. X. Liu, Lin Gu, R. K. Singh, L. Budd, M. van Schilfgaarde, M. R. McCartney, David J. Smith, N. Newman. 2002-12-18. Synthesis, characterization and modeling of high quality ferromagnetic Cr-doped AlN thin films. https://doi.org/10.1063/1.1570521

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