Room temperature positive exchange bias in CoFeB/D019-Mn3Ge noncollinear antiferromagnetic thin films

Polycrystalline , single crystal antiferromagnetic D019-Mn3Ge thin films were grown by magnetron sputtering on GaN specialIntscript and Pt specialIntscript templates at different substrate temperatures. Later, a CoFeB layer was grown on top of the D019-Mn3Ge films at room temperature. Single crystal D019-Mn3Ge thin films, with high surface roughness, induced an increase of the coercivity of the CoFeB ultrathin films, meanwhile polycrystalline D019-Mn3Ge thin films, with uniaxial texture and low surface roughness, induced positive exchange bias at room temperature by cooling the sample under a magnetic field of 2 T. No exchange bias was observed with lower cooling magnetic fields. The non-zero magnetic moment of uncompensated D019- Mn3Ge grains of the textured films couple antiferromagnetically leading to positive exchange bias.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Polycrystalline and single crystal antiferromagnetic D019-Mn3Ge thin films were grown using magnetron sputtering on GaN and Pt templates at different substrate temperatures. A CoFeB layer was subsequently grown on top of the D019-Mn3Ge films. Single crystal D019-Mn3Ge films with high surface roughness increased the coercivity of the CoFeB ultrathin films, while polycrystalline D019-Mn3Ge films with uniaxial texture and low surface roughness induced positive exchange bias at room temperature. The non-zero magnetic moment of uncompensated D019-Mn3Ge grains in the textured films led to the positive exchange bias.