Preparation and characterization of LaB6 ultra fine powder by combustion synthesis

High-purity, homogeneous and ultra fine LaB6 powders were prepared by combustion synthesis. The effects of reactant ratio and molding pressure on the phase and morphology of the combustion products were studied. The combustion products and leached products were analyzed by XRD, SEM and EDS. The results indicate that the combustion product consists of LaB6, MgO and a little Mg3B2O6. The combustion product becomes denser and harder when the molding pressure increases. The purity of LaB6 is higher than 99.0%. The LaB6 particle size is in range of 1.92–3.00 μm and the lattice constant of LaB6 is a=0.414 8 nm.