Indication of hysteresis in AlMnN

Abstract

AlN films grown by gas-source molecular beam epitaxy were doped with different levels of Mn during growth. High resolution x-ray diffraction characterization revealed good crystallinity in single phase material, with lattice constant decreasing with increasing Mn concentration. Single phase AlMnN was found to be p type while AlMnN/AlMn mixed phase material was found to be highly conductive n type. Magnetization measurements performed with a superconducting quantum interference device magnetometer indicated ferromagnetism in single phase material persisting to 300 K and showed no evidence of room temperature magnetization in multiphase material. In particular, it was shown that Mn4N second phases are not contributing to the magnetization in the AlMnN under optimized growth conditions.