Perpendicular magnetic anisotropy of (001)-textured poly-crystalline MnAlGe films

Takahide Kubota,Mingling Sun,Rie Y Umetsu,Keita Ito,Yohei Kota,Koki Takanashi,Masaki Mizuguchi

doi:10.1063/1.5130388

Abstract

Cu2Sb-type intermetallic compound, MnAlGe, is known to exhibit uniaxial magnetocrystalline anisotropy and relatively small saturation magnetization, which is suitable for spintronic application, e.g. spin-transfer phenomena requiring small critical current density. Ge-concentration dependence of the crystal structures, saturation magnetization, Ms, and perpendicular magnetic anisotropy, Ku was investigated for MnAlGe films prepared onto silicon substrates with a thermally oxidized amorphous layer. For the stoichiometric and Ge-rich samples, the films exhibited (001)-texture with perpendicular magnetization. The maximum values of Ms and Ku were 270 emu/cm3 and 4.8 × 106 erg/cm3, respectively, which were comparable values with those reported for bulk and epitaxially grown films in literatures.

Highlights

Cu2Sb-type intermetallics, (XX’)Z, form a crystal structure shown in Figure 1 which is a tetragonal C38 phase of the space group P4/nmm, No 129
Ge-concentration dependence of the crystal structures, saturation magnetization, Ms, and perpendicular magnetic anisotropy, Ku was investigated for MnAlGe films prepared onto silicon substrates with a thermally oxidized amorphous layer
The diffractions from the silicon substrates and an unknown phase are marked by ∗ and ▽, respectively

Summary

INTRODUCTION

Cu2Sb-type intermetallics, (XX’)Z, form a crystal structure shown in Figure 1 which is a tetragonal C38 phase of the space group P4/nmm, No 129. In addition to the magnetic properties, the MnAlGe and the related compounds, such as (Mn-Cr)AlGe offer another merit of relatively stable (001)-oriented film growth,[11–13] which fits with MgO-based magnetic tunnel junctions with the (001)-orientation for large tunnel magnetoresistance.[14,15]. The crystal structure and magnetic properties of MnAlGe in film form have been investigated intensively for epitaxially grown samples, and the dependence on film compositions was reported.[16,17]. For the poly-crystalline MnAlGe films, the literature reported perpendicular magnetization,[13] the details for crystal structures and quantitative magnetic properties has been unclear. Ge concentration dependence is investigated in poly-crystalline Mn-Al-Ge films

EXPERIMENTAL PROCEDURES

RESULTS AND DISCUSSION

SUMMARY