Synthesis of SmCo5 nanoparticles with small size and high performance by hydrogenation technique

SmCo5 nanoparticles (NPs) have promising applications in high-density magnetic storage and magnetic nanocomposites. In this work, A novel method to yield SmCo5 particles with small size and high coercivity was reported. Firstly, Sm2O3-Co NPs with size of 6-15nm were fabricated by a solvothermal route. Then the agglomerated SmCo5 particles were obtained by thermal reduction of the precursor, which show high coercivity of 2.0T at room temperature. At last, the as-synthesized SmCo5 particles were further hydrogenated under high hydrogen pressure of 4MPa at room temperature, where hydrogen absorption process could form small-sized SmCo5Hx particles due to their lattice expansion and hydrogen desorption process could convert SmCo5Hx NPs into SmCo5 NPs. The prepared SmCo5 NPs after hydrogenation, showing well distribution, have a small size of 5-20nm and room temperature coercivity of 1.22T.