Sol-Gel synthesis and phase evolution studies of yttrium silicates

Abstract

Yttrium silicate powders were synthesised through acid catalysed sol-gel route using Y(NO3)3.6H2O and tetra ethyl ortho silicate (TEOS) as precursors. The crystallographic phases evolved from the prepared gel on calcination at 1100°C were correlated with the experimental parameters used for synthesis. The optimised experimental condition resulted in well defined and crystallised phases of Yttrium disilicate (YDS), yttrium monosilicate (YMS) and biphasic mixture (YDS + YMS) powders on calcinations to 1100°C to 1500°C for 2 h. Surface morphology and structure of the final powders were investigated by XRD, SEM, particle size analysis, FTIR and Raman spectroscopy. The powders show particle size in the range 0.8 μm to 10μm. The YDS, YMS and YDS + YMS powders were pelletised and sintered at 1400°C for 2 h leading to 83 ± 1% dense products.