Enhanced perpendicular magnetic anisotropy of ferrimagnetic Mn₄N films deposited on the glass substrate

Mn4N films have been prepared on the glass substrate by reactive magnetron sputtering, using Mn3N2 as the seed layer. Compared with Mn4N film directly grown on the glass substrate, the crystallinity and perpendicular magnetic anisotropy (PMA) of the Mn4N film with the seed layer are significantly enhanced. By varying the thickness of the Mn3N2 seed layer, the structural and magnetic properties are systematically investigated. It is shown that the seed layer thickness is pivotal in the growth of Mn4N with good crystallinity. The crystallinity of Mn4N first improves with the increase in the layer thickness of Mn3N2, and degrades after an optimal thickness; this is related to the change in the surface roughness of the Mn3N2 layers. The Mn3N2 layer not only promotes the growth of Mn4N film with c-axis orientation, but also provides additional N atoms to the growing surface to prevent Mn4N from being oxidized. This simple method can be used to prepare high-quality Mn4N films on a glass substrate, which show strong PMA and are suitable for spintronics applications.