TY - JOUR
T1 - The role of one-dimensional magnetic nanoprecipitates on the magnetoresistance of soft magnetic alloys
T2 - Study of a melt-spun Cu–Co alloy
AU - Suguihiro, Natasha M.
AU - Torres, Wilmar S.
AU - Nunes, Wallace C.
AU - Saitovitch, Elisa B.
AU - Mc Cartney, Martha R.
AU - Smith, David J.
AU - Costa, Antonio M.L.M.
AU - Solórzano, I. Guillermo
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - This work has investigated the microstructure and magnetic properties of supersaturated melt-spun Cu–10%Co alloys by means of magnetization, magnetotransport studies, electron microscopy and electron holography. Our results demonstrate that the microstructure of the annealed supersaturated alloys is constituted by two different types of Co-rich phases: spherical Co-rich precipitates as a result of spinodal decomposition, and Co rod-like precipitates, as a result of discontinuous grain-boundary precipitation. The aspect ratio of such precipitates is quite high, exhibiting magnetic anisotropy along their long axes, which generates global anisotropy of the alloy sample. We verified that the highest giant magnetoresistance occurs concurrently with an optimum discontinuous precipitate development. Electron holography reveals an antiferromagnetic coupling of the Co rods in the remanent magnetization state. The magnetization and magnetoresistance curves as a function of applied magnetic field are well described by an independent-moment approach considering the sum of the average magnetic moments of the spherical and the rod-like Co precipitates.
AB - This work has investigated the microstructure and magnetic properties of supersaturated melt-spun Cu–10%Co alloys by means of magnetization, magnetotransport studies, electron microscopy and electron holography. Our results demonstrate that the microstructure of the annealed supersaturated alloys is constituted by two different types of Co-rich phases: spherical Co-rich precipitates as a result of spinodal decomposition, and Co rod-like precipitates, as a result of discontinuous grain-boundary precipitation. The aspect ratio of such precipitates is quite high, exhibiting magnetic anisotropy along their long axes, which generates global anisotropy of the alloy sample. We verified that the highest giant magnetoresistance occurs concurrently with an optimum discontinuous precipitate development. Electron holography reveals an antiferromagnetic coupling of the Co rods in the remanent magnetization state. The magnetization and magnetoresistance curves as a function of applied magnetic field are well described by an independent-moment approach considering the sum of the average magnetic moments of the spherical and the rod-like Co precipitates.
KW - Discontinuous nanorod precipitation
KW - Granular systems
KW - Magnetic one-dimensional nanoparticles
KW - Magnetoresistance
KW - Supersaturated Cu–Co alloys
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U2 - 10.1016/j.matchemphys.2021.124517
DO - 10.1016/j.matchemphys.2021.124517
M3 - Article
AN - SCOPUS:85103663986
SN - 0254-0584
VL - 266
JO - Materials Chemistry and Physics
JF - Materials Chemistry and Physics
M1 - 124517
ER -