Single Step Solid-State Synthesis of Lanthanum Molybdate

Abstract

In this study, LaxMoyOz powders were synthesized by a cost-effective solid-state synthesis method. Four different heating cycles were designed to investigate the effects of synthesis temperature and holding time on lanthanum molybdate (LMO) formation, phase assemblies, particle size and morphology. X-Ray Diffraction (XRD) and scanning electron microscopy (SEM) studies were performed to observe crystal structure and particle morphology of synthesized powders. The results showed that nearly ninety percent beta - La2Mo2O9 (43,3 nm crystal size) phase was obtained at 1000 degrees C for 6 h holding time. Longer holding times at 1000 degrees C favor more oxygen-rich compounds which cause recrystallization of various new crystalline phases. The grain size of the synthesized powder was increased from 0,2 mu m to 1,5 mu m with increasing holding time. In summary, it is possible to manufacture LMO powders rich in beta - La2Mo2O9 by one - step solid - state synthesis method. The phase assembles and particle size of LMO powders could also be tailored by optimization of heat treatment cycle.