Room temperature ferromagnetic properties of transition metal implanted Al0.35Ga0.65N

A nominally undoped MBE-grown Al0.35Ga0.65N thin film was implanted with Cr, Mn, and Ni with an energy of 200 keV to a dose of 5 × 1016 cm−2 for Cr and Mn and to a dose of 3 × 1016 cm−2 for Ni. The magnetic properties of these samples were measured using a superconducting quantum interference device (SQUID) magnetometer. The Cr-implanted Al0.35Ga0.65N annealed at 750 °C has a coercive field (HC) of 178 Oe at 300 K, and field-cooled (FC) and zero-field-cooled (ZFC) magnetization measurements show evidence of ferromagnetism in this sample with an estimated Curie temperature of around 350 K. The Mn-implanted sample has an HC of 180 Oe at 300 K after annealing at 750 °C for 5 min, which indicates a dominant ferromagnetic phase. The Ni-implanted Al0.35Ga0.65N produces clear ferromagnetic hysteresis at temperatures up to 350 K. FC–ZFC magnetization separation suggests the true presence of ferromagnetism in this material.