Modulating the magnetic anisotropy in SmCo/Co nanocomposites through alteration in spin-orbit coupling

In the present work, one-dimensional (1-D) as-synthesized SmCo/Co magnetic nanocomposites were prepared through magnetically-assisted chemical reduction method. The samples were prepared with the varying reaction times between 1 and 10 h labelled as SC1, SC2, SC5, SC7 and SC10. The Rietveld refinement of XRD patterns revealed the presence of Sm(OH)3 (P63/m), hcp-Co (P63/mmc), cubic-Co (Fm-3 m) and Sm2Co17 (P63/mmc) phases with varying phase fractions. The nanocomposites were found to possess the highest aspect ratio (-7) with lowest crystallite size (-50 nm) along with the highest developed lattice strain in SC5. The decisive influence of the reaction time was observed on the magnetic response of the samples indicating highest saturation magnetization of - 150 emu/g and effective magnetic anisotropy of - 1.5 x 106 erg/cm3 in SC5. The generalized form of Bloch law was employed to study the origin of magnetic anisotropy determined as spin-orbit coupling which was found to be highest in SC5. It was suggested that the enhanced magnetic properties of the nanocomposites are attributable to the high fraction of magnetic phases with the soft magnetic character and coupling between multiple phases.