Role of growth conditions on magnetic properties of AlCrN grown by molecular beam epitaxy

Abstract

AlCrN layers were grown by gas source molecular beam epitaxy with varying amounts of Cr (up to $\sim 3\mathrm{at.}\%$ ) under a broad range of Cr cell temperatures and V/III ratio. Magnetic measurements performed in a superconducting quantum interference device magnetometer showed evidence of ferromagnetism up to $350\mathrm{K}$ in single phase material. Magnetization dependence on dopant cell temperature and V/III was used to optimize the growth conditions of the AlCrN layers. The single-phase material was highly insulating $(\sim {10}^{10}\Omega \mathrm{cm})$ , while the material containing second phases (predominantly ${\mathrm{Cr}}_2\mathrm{N}$ and ${\mathrm{Al}}_x{\mathrm{Cr}}_y$ ) was conducting with resistivity of order $1000\Omega \mathrm{cm}$ . High resolution x-ray diffraction rocking curves indicated high crystalline quality in the single phase material.