Intrinsic ferromagnetism in 4H-SiC single crystal induced by Al-doping

SiC single crystals with varying Al doping concentrations are grown through top-seeded solution growth method to explore the intrinsic magnetism upon non-magnetic element doping. Ferromagnetism is detected in all Al-doped crystals, where an enhancement in magnetization and magnetic anisotropy upon increasing concentrations of Al doping is observed. The coercive force and magnetic remanence enhance with increasing Al-concentration while the Curie temperatures fluctuate around 30 K. Anisotropy in magnetic hysteresis is observed when the applied magnetic field is going from perpendicular to parallel to the (0 0 0 1) plane. Based on the measured carrier concentrations and the proposed structural models of Al dopant plus Si vacancies, we claim that the extra free carriers introduced by Si vacancies around Al atoms are vital to the emergence of the ferromagnetism in SiC.