Copper-doped AlN polycrystalline powders: A class of room-temperature ferromagnetic materials

Cu-doped AlN polycrystalline samples were synthesized by a solid-state reaction. X-ray diffraction analysis revealed the hexagonal structure of the doped samples. Photoluminescence measurements reveal the substitution of Cu for Al in the AlN lattice. Clear hysteresis loops are observed in the M – H curves for the samples at 300 K, revealing room temperature ferromagnetism of the samples. Our experimental results verify that room temperature ferromagnetism is an intrinsic property of Cu-doped AlN.