Rich polymorphism of Sm2WO6 using the mechanical activation method

Abstract

The phase formation of samarium tungstate (Sm₂WO₆) from a mechanically activated oxide mixture of Sm₂O₃ : WO₃ = 1 : 1 was studied using thermal analysis methods. The microstructure of the powder samples and high-temperature ceramics was examined by SEM. The influence of activation in mills with different specific power intensities was considered: a high-energy mill designed by Aronov and a SPEX 8000M mill. The conditions for obtaining polycrystalline samples of new modifications, β-Sm₂WO₆, α-Sm₂WO₆ and δ-Sm₂WO₆, whose existence is reported here for the first time, have been determined. The structures of the new polymorphs were characterized by XRD with Rietveld refinement and Raman spectroscopy.