Phase characterization of Sm–Lu mixed oxide powders prepared by sintering and radio frequency plasma spraying

Radio frequency plasma spraying is a promising technique 10 prepare rare earth oxide nano-particles. Applying this method after sintering of pellets at T = 1600 degrees C and subsequent grinding, Sm2O3-Lu2O3 mixed oxide powders of various compositions were synthesized. Analyzing the ground powders, the phase field call be divided into three regions: (1) Sm-rich monoclinic B-type solid solutions, (2) Lu-rich cubic C-type solid Solutions, and (3) a diphasic region for Lu Contents 0.33 <= X-Lu <= 0.54. In the single phase areas, the Volume for one formula unit of the rare earth sesquioxide is found to depend linearly on the Cubed average cation radius. Plasma spraying of the Lu-rich powders leads to a second monoclinic B-type phase. Excluding the Solubility gap, the monoclinic lattice parameters show quadratic dependencies oil the Lu content and the molecular volume is a function of third order on the cation radius.