Effect of Annealing on Perpendicular Magnetic Anisotropy and Low Saturation Magnetization of MgO/Co2FeAl/Mo Trilayer Films

In this study, we report our approach to manipulate the strength of perpendicular magnetic anisotropy (PMA) at oxide/ferromagnetic metal of Heusler alloy (HA) interface by tuning the parameter of annealing temperature. Robust PMA energy density (Keff) of ∼\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\sim $\end{document} 0.43 ×\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\times $\end{document} 106 erg/cm3 and small saturation magnetization (Ms) as low as ∼\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\sim $\end{document} 248 emu/cm3 have been achieved for MgO/Co2FeAl (CFA)/Mo stacks at 400 ∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$^{\circ }$\end{document}C. We identify that PMA energy is thermally stable up to the maximum temperature of 400 ∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$^{\circ }$\end{document}C. Effect of annealing temperature on surface morphology, grain distribution, and surface roughness of the stacks are investigated by atomic force microscopy (AFM). Further, X-ray photoelectron spectroscopy (XPS) study demonstrates that the interfacial oxidation decides the strong PMA property at MgO/Co2FeAl interface during the annealing process. This MgO/CFA/Mo trilayer system can be a suitable candidate for the development of low-power consumption, huge-density data storage, high-thermal stability against the annealing temperature, and nonvolatile magnetic memories.