TY - JOUR

T1 - On the magnetic nanostructure of a Co–Cu alloy processed by high-pressure torsion

AU - Stückler, Martin

AU - Teichert, Christian

AU - Matković, Aleksandar

AU - Krenn, Heinz

AU - Weissitsch, Lukas

AU - Wurster, Stefan

AU - Pippan, Reinhard

AU - Bachmaier, Andrea

N1 - Publisher Copyright: © 2020 The Authors

PY - 2021/3

Y1 - 2021/3

N2 - In this study, a preparation route of Co–Cu alloys with soft magnetic properties by high-pressure torsion deformation is introduced. Nanocrystalline, supersaturated single-phase microstructures are obtained after deformation of Co–Cu alloys, which are prepared from an initial powder mixture with Co-contents above 70 wt.%. Isochronal annealing treatments up to 400 °C further reveal a remarkable microstructural stability. Only at 600 °C, the supersaturated phase decomposes into two fcc-phases. The coercivity, measured by SQUID as a function of annealing temperature, remains significantly below the value for bulk-Co in all states investigated. In order to understand the measured magnetic properties in detail, a quantitative analysis of the magnetic microstructure is carried out by magnetic force microscopy and correlated to the observed changes in coercivity. Our results show that the rising coercivity can be explained by a magnetic hardening effect occurring in context with spinodal decomposition.

AB - In this study, a preparation route of Co–Cu alloys with soft magnetic properties by high-pressure torsion deformation is introduced. Nanocrystalline, supersaturated single-phase microstructures are obtained after deformation of Co–Cu alloys, which are prepared from an initial powder mixture with Co-contents above 70 wt.%. Isochronal annealing treatments up to 400 °C further reveal a remarkable microstructural stability. Only at 600 °C, the supersaturated phase decomposes into two fcc-phases. The coercivity, measured by SQUID as a function of annealing temperature, remains significantly below the value for bulk-Co in all states investigated. In order to understand the measured magnetic properties in detail, a quantitative analysis of the magnetic microstructure is carried out by magnetic force microscopy and correlated to the observed changes in coercivity. Our results show that the rising coercivity can be explained by a magnetic hardening effect occurring in context with spinodal decomposition.

KW - High-pressure torsion

KW - Magnetic force microscopy (MFM)

KW - Nanocrystalline

KW - Severe plastic deformation (SPD)

KW - Supersaturation

KW - magnetic nanostructure

UR - http://www.scopus.com/inward/record.url?scp=85088874327&partnerID=8YFLogxK

U2 - 10.1016/j.jsamd.2020.09.013

DO - 10.1016/j.jsamd.2020.09.013

M3 - Article

AN - SCOPUS:85088874327

VL - 6.2021

SP - 33

EP - 41

JO - Journal of science / Vietnam National University / Advanced materials and devices

JF - Journal of science / Vietnam National University / Advanced materials and devices

SN - 2468-2179

IS - March

ER -