A facile synthesis of high performance SmCo₅ nanoparticles

SmCo₅ nanoparticles have promising applications in high-density magnetic storage and magnetic nanocomposites. A combination of solution-phase synthesis and calciothermic reduction shows obvious advantage for preparing rare-earth hard magnetic nanoparticles. In this process, the Sm₂O₃ precursor was previously prepared in organic solvent, leading to a low coercivity due to the presence of CoC in SmCo₅ nanoparticles. In this paper, a facile procedure for fabricating high performance ferromagnetic, crystalline SmCo₅ nanoparticles in inorganic system is approached. 10-40nm SmCo₅ nanoparticles have been prepared with the coercivity of 20.0kOe by reductive annealing of amorphous Sm(OH)₃ and Co(OH)₂ precursor at 900°C. Thereinto, the addition of CaO can effectively prevent the particles growth. While, polycrystalline Sm₂Co₁₇ particles with stackable sheet morphology have been obtained by reduction of crystalline Sm(OH)₃ and Co(OH)₂ at 1100°C. This environmentally friendly method avoids the presence of CoC successfully and improves the coercivity up to 20.0kOe.