Epitaxial Co₅₀Fe₅₀(110)/Pt(111) films on MgAl₂O₄ (001) and its enhancement of perpendicular magnetic anisotropy

Perpendicular magnetic anisotropy (PMA) in magnetic thin films with low coercivity is desirable for magnetic memory devices. It has been discovered that a (111)-oriented or textured Pt seed layer can enhance PMA and is, therefore, commonly utilized in spintronic structures. We grow (111)-oriented Pt epitaxial films via off-axis sputtering on various substrates and investigate the optimal substrate and orientation for high quality, epitaxial growth. Our results show that Pt(111) epitaxial films grow remarkably well on MgAl₂O₄(001) with an exceptionally narrow X-ray diffraction rocking curve. This high-quality seed layer is determined to promote epitaxial growth of Pt/Co₅₀Fe₅₀/Pt trilayers with strong PMA comparable to many repeats of the magnetic multilayers reported previously. In addition, the Pt seed layer enhances the maximum thicknesses of Co₅₀Fe₅₀ that can still maintain PMA up to 1.07 nm.