Highly Reduced Saturation Magnetization in Epitaxially Grown Ferrimagnetic Heusler Thin Films

Abstract

The key of spintronic devices using the spin-transfer torque phenomenon is the effective reduction of switching current density by lowering the damping constant and the saturation magnetization while retaining strong perpendicular magnetic anisotropy. To reduce the saturation magnetization, particular conditions such as specific substitutions or buffer layers are required. Herein, we demonstrate highly reduced saturation magnetization in tetragonal D022 Mn3–xGa thin films prepared by rf magnetron sputtering, where the epitaxial growth is examined on various substrates without any buffer layer. As the lattice mismatch between the sample and the substrate decreases from LaAlO3 and (LaAlO3)0.3(Sr2AlTaO6)0.7 to SrTiO3, the quality of Mn3–xGa films is improved together with the magnetic and electronic properties. Especially, the Mn3–xGa thin film epitaxially grown on the SrTiO3 substrate, fully oriented along the c axis perpendicular to the film plane, exhibits significantly reduced saturation magnetization as low as 0.06 μB, compared to previous results. By the structural and chemical analyses, we find that the predominant removal of Mn II atoms and the large population of Mn3+ ions affect the reduced saturation magnetization. Our findings provide insights into the magnetic properties of Mn3–xGa crystals, which promise great potential for spin-related device applications.

First-Principles Calculations to Investigate the Stability and Thermodynamic Properties of a Newly Exposed Lithium–Gallium–Iridium-Based Full-Heusler Compound

“…Several researchers from all over the world have focused on Heusler metals because of their tunable properties, including their high Curie temp, tunable electronics structure, acceptable semiconducting lattice parameter, and varied magnetic property. − Heusler alloy intermetallic compounds are attractive options for thermoelectric materials − and topological insulators. , They can also be used as shape-memory materials, spin-gapless semiconductors, and other forms of thermoelectric materials. − Heusler substances can be broadly categorized into half-Heusler, full-Heusler, and last, quaternary-Heusler. These structures’ stoichiometric configurations are XYZ, XY 2 Z, and XYMZ, in which X, Y, and M are typically transition metals and Z is the leading group component. − XY 2 Z, a full-Heusler configuration, settles in a cubic L2 1 arrangement (MnCu 2 Al-sample) with the spatial group Fm 3̅ m (# 225). ,, In this article, we will investigate the physical characteristics of one such type.…”