Effects of thermal annealing on structural and magnetic properties of Mn ions implanted AlInN/GaN films

Abstract

In the search of functional diluted magnetic semiconductors, a study of effects of Mn ions implantation on structural and magnetic properties of AlInN/GaN/sapphire films is reported. Mn ions at 200 keV were implanted into the layers at three doses 5 × 1014 cm−2, 5 × 1015 cm−2 and 5 × 1016 cm−2. The as-implanted samples were thermally annealed and investigated by using X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS) and vibrating sample magnetometry (VSM). The structural analysis of the samples indicated that the sample implanted at dose of 5 × 1014 cm−2 and thermally annealed at 750 °C exhibited good crystalline recovery. The ferromagnetism of the samples was investigated by recording magnetization as a function of applied magnetic field. The magnetic characterizations exhibited well shaped hysteresis at room temperature which indicates presence of high temperature ferromagnetism in the samples. The findings of this work pointed out that AlInN/GaN samples implanted with Mn ions at dose of 5 × 1016 cm−2 and annealing at 750 °C exhibited maximum magnetization. On the basis of first principles calculations, it is predicted that p–d interaction is the mechanism of ferromagnetic ordering in the material.