Influence of Mn-Doped Content on Ferromagnetism of Ga_1-xMn_xN Film Grown by LP-MOVPE

The diluted magnetic semiconductor Ga_1-xMn_xN was achieved by low-pressure metal organic vapour-phase epitaxy (LP-MOVPE). Proton-induced x-ray emission was employed non-destructively, quickly and accurately to determine the Mn-doped content. The magnetic property was measured by a superconducting-quantum-interference-device (SQID) magnetometer. Apparent ferromagnetic hysteresis loops measured at or above room temperature are presented. No ferromagnetic secondary phases were detected by high-resolution x-ray diffraction. The experimental results show that the ferromagnetic signal firstly decreases and then increases with the increasing Mn-doped content from 0.23% to 4.69% and it is the weakest when Mn content is 0.51%. The annealing treatment could make the ferromagnetic property stronger.