Synthesis of bulk nanocrystalline samarium hexaboride

Abstract

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.