The effects of processing parameters on molten salt synthesis of CaZrO3 nano-powders using oxide precursors

• Published in: Powder technology 2014-05, Vol.257, p.149-155
• Main Authors: Fazli, Rahman, Golestani-Fard, F.
• Format: Article
• Language: English
• Subjects: Applied sciences; Calcium zirconate; Chemical engineering; Crystallization, leaching, miscellaneous separations; Exact sciences and technology; Miscellaneous; Molten salt method; Nano materials; Solid-solid systems; Template growth
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2014.02.058

Nano-powders of CaZrO3 were successfully synthesized at 650°C using the molten-salt method, and the effects of processing parameters, such as temperature, holding time and amount of salt on the crystallization of CaZrO3 were investigated. CaCl2, LiCl, CaCO3 and nano-ZrO2 were used as starting materials. On heating, CaCl2–LiCl molten eutectic salt provided a liquid medium for reaction of CaCO3 and ZrO2 to form CaZrO3. The results demonstrated that CaZrO3 started to form at about 550°C and that, after the temperature was increased to 1000°C, the amounts of CaZrO3 in the resultant powders increased with a concomitant decrease in CaCO3 and ZrO2 contents. After washing with hot-distilled water, the samples heated for 3h at 650°C were single-phase CaZrO3 with 90–95nm particle size. Furthermore, the synthesized CaZrO3 particles retained the size and morphology of the ZrO2 powders, which indicated that a template formation mechanism dominated the formation of CaZrO3 by molten-salt method. [Display omitted] •Nano-CaZrO3 was synthesized via molten salt method.•Optimum temperature, holding time and salt to oxide ratio were 650°C, 3h and 2:1.•Particle size of synthesized CaZrO3 was 90–95nm.•“Template–growth” was dominant mechanism in synthesis process.•Synthesized nano-CaZrO3 powders were pure.