Preparation of cubic Na0.5Sr0.25NbO3 particles by molten salt synthesis

Abstract

Pure Na 0.5 Sr 0.25 NbO 3 particles were successfully synthesized using the molten salt synthesis method in the SrCO 3 ?Nb 2 O 5 ?KCl?NaCl system, which could not be obtained in the SrCO 3 ?Nb 2 O 5 ?NaCl system. The result suggested that the fabrication process of Na 0.5 Sr 0.25 NbO 3 was different for the two systems. In the SrCO 3 ?Nb 2 O 5 ?NaCl system, NaSr 2 Nb 5 O 15 formed and then converted into Na 0.5 Sr 0.25 NbO 3 . In the SrCO 3 ?Nb 2 O 5 ?KCl?NaCl system, Na 0.5 Sr 0.25 NbO 3 could be obtained directly by the reaction between the intermediate KSN and NaCl. The effects of the NaCl salt content and heated temperature on the purity and size of particles were investigated. Pure Na 0.5 Sr 0.25 NbO 3 powder crystals with uniform particle size could be prepared at the heated temperature of 1,200°C and NaCl salt-to-oxide ratio of 2, which were ideal raw material for preparing Na 0.5 Sr 0.25 NbO 3 ceramics.

The synthesis of SiCON ceramics through precursor method

“…From Figure 5 (Curve c), it could be found that the peak of SiH disappeared at 500°C, where the dehydrogenation reaction between SiH, NH and SiH, SiH took place. Besides, the intensity of NH diminished, which was caused by the release of ammonia at about 150–500°C 20. As shown in Figure 5 (Curve d), the intensity of SiCH 3 decreased, and the peaks of CH 3 and CH 2  disappeared due to the free radical reaction that occurred at the temperature of 400–800°C,21 whereas the peak of SiH appeared again, which is probably owing to the decomposition of SiCH 3 into SiH 10.…”

Progress on the fabrication of lead-free textured piezoelectric ceramics: perspectives over 25 years

“…Several routes have been used to synthesize ceramic powders, e.g. hydrothermal [29][30][31][32], chemical [33,34], and molten salts synthesis (MSS) [35][36][37][38]. MSS allows great flexibility by adjustment of reaction conditions such as synthesis temperature, soaking time and weight ratio between salt and oxides, in order to obtain the desired characteristics of the synthesized product particles.…”