Spray drying mass-production route for Mg-doped LiNbO3 (Mg:LN) polycrystalline powder based on a wet-chemical method

Abstract

A mass production route for Mg-doped LiNbO₃ (Mg:LN) polycrystalline powder was proposed based on a wet-chemical method/spray drying process. A stable homogenous precursor solution was prepared by dissolving commercial Nb(OH)₅, Li₂CO₃ and MgO, and was stabilized with citric acid (CA) as a chelating agent. Spherical Mg:LN precursor powder can be obtained by a spray-drying method, and spherical mono-phase perovskite Mg:LN polycrystalline powder with uniform size was obtained by calcining the precursor powder at relatively low temperature. Thermogravimetry–differential thermal analysis (TG–DTA), X-ray diffraction (XRD), infrared spectroscopy and scanning electron microscopy (SEM) were used to characterize the precursor and product powder. The as-obtained Mg:LN powder was used for Mg:LN single-crystal growth. The obtained Mg:LN single crystal possesses both high optical homogeneity and ingredient uniformity. This mass production route for preparation of Mg:LN powder provides a solution to the problem of defects in Mg:LN single crystals caused by nonhomogeneity of magnesium distribution.