Preparation of nano-particles LiTaO3 powders by the polymeric precursor method

摘要

Lithium tantalate (LiTaO3) nano-powders with Li/Ta= 1:1 stoichiometry were synthesized by the polymeric precursor method. The desired metal cations were chelated in an aqueous solution with citric acid as chelating agent and ethylene glycol as etherification agent. The thermal decomposition of the precursor gels were studied by thermogravimetry-differential thermal analysis (TG/DTA). The phase transformation of LiTaO3 powders with different calcinating temperatures were studied by X-ray diffraction (XRD). The scanning electron microscope （SEM） images were taken in order to estimate the size and show the surface morphology of the LiTaO3 powders. The influence of two test routes on surface morphology and grain size of the powders was sutdied. Homogeneous precursor solution and gels with no precipitate can be achieved at the test routeⅠ. The results reveal that the precursor gels heat treated at 600℃, the corresponding XRD data exhibit diffraction peaks belonging to the formation of LiTaO3, which suggests the beginning of crystallization. A pure nano-powders LiTaO3 with fine average grain size of ～50nm are achieved from precursor gels calcined at 700℃.