LIU Mengting 1, LIU Jianmin 2, JIANG Weihui 1, 2, JIANG Feng 1, FENG Guo 1, WANG Tao 1, WANG Sanhai 1
(1. School of Material Science and Engineering, Jingdezhen Ceramic University, Jingdezhen 333403, Jiangxi, China; 2. National Engineering Research Center for Domestic and Building Ceramics, Jingdezhen 333001, Jiangxi, China)
Abstract: NaZr2(PO4)3 powders were prepared by using a simple low-temperature solid reaction, with zirconium oxychloride octahydrate (ZrOCl2·8H2O), sodium dihydrogen phosphate dihydrate (NaH2PO4·2H2O) as the raw materials and ethylene glycol (CH2OH)2 as grinding agent. The effect of calcination temperature on properties of the sodium fast ion conductor NaZr2(PO4)3 powders was studied by using DSC-TG, XRD, FE-SEM and Raman techniques, while the corresponding formation mechanism was also discussed. It was found that homogeneous NaZr2(PO4)3 powders were obtained after calcination at 810 ℃ for 5 h, with an average particle size of about 0.5 μm. The solid phase reaction was beneficial to the formation of Zr(HPO4)2·H2O during the grinding process, thus favoring the production of NaZr2(PO4)3 at relatively low temperatures. In addition, the combination of the in-situ produced NaCl with NaPO3 triggered the formation of low eutectic salt, contributing to the growth of well-dispersed NaZr2(PO4)3 crystalline powders, owing to the production of liquid phase.
Key words: sodium zirconium phosphate; molten salt; calcination temperature; formation mechanism