Synthesis of hard magnetic α-MnBi phase by high pressure torsion and field assisted annealing

• DOI: 10.1016/j.jmmm.2023.171082
• Publication Date: 2023-07-27T11:08:18Z
• Authors: Lukas Weissitsch; Stefan Wurster; Martin Stückler; Timo Müller; Heinz Krenn; Reinhard Pippan; Andrea Bachmaier
• Keywords: Condensed Matter - Materials Science; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; info:eu-repo/classification/ddc/530; 530

Bulk composites using powder blends of Mn and Bi with equal atomic ratios are consolidated severely deformed by high-pressure torsion (HPT). Subsequent annealing treatments lead to the formation ferromagnetic rare-earth free hard magnetic α-MnBi phase. The initial phase is studied in-situ high-energy XRD experiments showing a beneficial influence HPT-deformation on amount α-MnBi. nucleation sites strongly increased, thus volumetric content exceeds 50 vol%. A lower HPT-pressure 2 GPa found be preferred over 5 obtain high contents. Annealing done or without applying an external field. Additionally, influences HPT-induced shear deformation discussed correlated diffusion path ways fostering anisotropic