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 -type GaP substrates are used. At low temperatures the saturated moment is on the order of 1 Bohr magneton, and the spin wave stiffness inferred from the Bloch-law dependence of the magnetization provides an estimate of the Curie temperature that exceeds the experimental value, . The presence of ferromagnetic clusters and hysteresis to temperatures of at least 330 K is attributed to disorder and proximity to a metal-insulating transition.
- Received 28 January 2002
DOI:https://doi.org/10.1103/PhysRevLett.89.107203
©2002 American Physical Society