Anisotropic Ferromagnetism in High Dose Iron Implanted Magnesium Oxide

Abstract

It was found that MgO single crystal implanted with iron ions exhibits a strong ferromagnetic response at room temperature and fourth-order in-plane magnetic anisotropy. The implanted iron impurity was found in different valence and phase states. A significant part of the impurity forms α-Fe nanoparticles. They are the main source of the observed ferromagnetism at room temperature. We suppose that these nanoparticles are coherently buried into the MgO host matrix. This explains the discovered magnetic anisotropy in the plane of the implanted surface.