Synthesis of bulk nanocrystalline samarium hexaboride

This study reports on the preparation and consolidation of nano-sized SmB₆ powders via mechanochemical synthesis (MCS) performed at room-temperature using Sm₂O₃-B₂O₃-Mg powder blends followed by cold pressing/pressureless sintering. Milling duration was used as an MCS parameter to reveal the optimum production conditions of nanoscale SmB₆ powders, which were subsequently subjected to HCl leaching to remove the intermediate products. Microstructural, physical and magnetic properties of the SmB₆ powders were evaluated using X-ray diffractometer (XRD), differential scanning calorimeter (DSC), particle size analyzer (PSA), stereomicroscope (SM), scanning electron microscope (SEM), transmission electron microscope/energy dispersive spectrometer (TEM/EDS), atomic absorption spectrometer (AAS), surface area analyzer (SAA) and vibrating sample magnetometer (VSM). The bulk properties of the SmB₆ sintered from nanocrystalline SmB₆ powders with an average particle size of ~80nm and a minimum purity of 99.99% were described in terms of their microstructure, density, electrical resistivity, surface roughness, friction coefficient, hardness and wear rate.