Hydrothermal and wet-chemical synthesis of pure LiTaO_3 powders by using commercial tantalum hydroxide as starting material

摘要

We report here the successful synthesis of lithium tantalate (LiTaO_3, LT) powders by using a combined hydrothermal and wet-chemical technique. This synthesis method involves only inexpensive, nontoxic raw materials, such as tantalum hydroxide (Ta(OH)_5) and lithium carbonate (Li_2CO_3). Ta(OH)_5 was first dissolved in hydrochloric acid through a hydrothermal process, followed by addition of citric acid (CA) to form stable Ta-CA complex. After pH adjustment with ammonia and addition of Li_2CO_3, pure LT powders were obtained by calcination at 720 deg C for 2 h. Compositional, microstructural, and morphological aspects of the final product were evaluated with X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Thermal behaviors and the calcination temperature were determined by thermal analysis.