Heteroepitaxial growth of tetragonal Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ (0 $\leqslant$ x $\leqslant$ 1.2) Heusler films with perpendicular magnetic anisotropy

TL;DR

This study demonstrates heteroepitaxial growth of Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ Heusler films with tunable magnetic properties and high perpendicular magnetic anisotropy, suitable for permanent magnet and spintronic applications.

Contribution

First demonstration of heteroepitaxial Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ films with controlled magnetic anisotropy and properties.

Findings

Films exhibit tetragonal D0$_{22}$ structure with (001) orientation.

High uniaxial anisotropy Ku ≥ 1.4 MJ/m³ and coercivity up to 0.95 T.

Optimal composition Mn$_{1.6}$Fe$_{1.1}$Ga$_{1.3}$ shows Ku of 1.47 MJ/m³ and (BH)$_{max}$ of 37 kJ/m³.

Abstract

This work reports on the structural and magnetic properties of Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ Heusler films with different Fe content x (0 $\leqslant$ x $\leqslant$ 1.2). The films were deposited heteroepitaxially on MgO single crystal substrates, by magnetron sputtering. Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ films with the thickness of 35 nm were crystallized in tetragonal D0$_{22}$ structure with (001) preferred orientation. Tunable magnetic properties were achieved by changing the Fe content x. Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ thins films exhibit high uniaxial anisotropy Ku $\geqslant$ 1.4 MJ/m3, coercivity from 0.95 to 0.3 T and saturation magnetization from 290 to 570 kA/m. The film with Mn$_{1.6}$Fe$_{1.1}$Ga$_{1.3}$ composition shows high Ku of 1.47 MJ/m3 and energy product ${(BH)_{max}}$ of 37 kJ/m3, at room temperature. These findings demonstrate that Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ films have promising properties for mid-range permanent magnet and spintronic applications.