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Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C

N. Theodoropoulou·A. F. Hebard·M. E. Overberg·C. R. Abernathy·S. J. Pearton·S. N. G. Chu·R. G. Wilson
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Abstract

Ion implantation of Mn ions into hole-doped GaP has been used to induce ferromagnetic behavior above room temperature for optimized Mn concentrations near 3 at.%. The magnetism is suppressed when the Mn dose is increased or decreased away from the 3 at.% value, or when n-type GaP substrates are used. At low temperatures the saturated moment is on the order of one Bohr magneton, and the spin wave stiffness inferred from the Bloch-law T^3/2 dependence of the magnetization provides an estimate Tc = 385K of the Curie temperature that exceeds the experimental value, Tc = 270K. The presence of ferromagnetic clusters and hysteresis to temperatures of at least 330K is attributed to disorder and proximity to a metal-insulating transition.

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N. Theodoropoulou, A. F. Hebard, M. E. Overberg, C. R. Abernathy, S. J. Pearton, S. N. G. Chu, R. G. Wilson. 2002-01-26. Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C. https://doi.org/10.1103/physrevlett.89.107203

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