Ru$_{2-x}$Mn$_{1+x}$Al thin films

TL;DR

This study reports the growth and characterization of Ru$_{2-x}$Mn$_{1+x}$Al thin films, revealing their ferrimagnetic metallic nature, moderate spin polarization, and the influence of atomic order and hybridization on their magnetic properties.

Contribution

It provides the first detailed analysis of Ru$_{2-x}$Mn$_{1+x}$Al thin films, highlighting their magnetic properties and the effects of atomic order and hybridization, which differ from similar compounds.

Findings

Highly spin-polarised ferrimagnetic metal with 50-60% spin polarization.

Weak magnetocrystalline anisotropy observed.

No ferrimagnetic compensation or large magneto galvanic effects.

Abstract

The cubic Heusler alloy Ru$_{2-x}$Mn$_{1+x}$Al is grown in thin film form on MgO and MgAl$_2$O$_4$ substrates. It is a highly spin-polarised ferrimagnetic metal, with weak magnetocrystalline anisotropy. Although structurally and chemically similar to $\text{Mn}_2\text{Ru}_x\text{Ga}$, it does not exhibit ferrimagnetic compensation, or large magneto galvanic effects. The differences are attributed to a combination of atomic order and the hybridisation with the group 13 element Al or Ga. The spin polarisation is around 50 to 60 %. There is a gap in the density of states just above the Fermi level in fully ordered compounds.