Fast magnetization precession and strong perpendicular magnetic anisotropy in ferrimagnetic Mn4N thin films improved by a Pd buffer layer

Ferrimagnetic Mn₄N thin films have low magnetization and perpendicular magnetic anisotropy (PMA), as required for fast and low current switching spintronics devices. However, there need to be improvements in the growth of epitaxial quality films with fast spin dynamics for such spintronic applications. Here we prepared Mn₄N thin films with a Pd buffer layer and investigated the crystalline structure and magnetic properties. We demonstrated that both crystalline quality and PMA of Mn₄N thin films are enhanced significantly due to the relaxation of tensile stress induced by the Pd buffer layer. We also demonstrated a fast magnetization precession at room temperature, almost 100 GHz. With the characteristics of high thermal stability, enhanced PMA by buffer layer, and fast magnetization precession, Mn₄N thin films are a promising material for spintronic applications.