Study of the formation mechanism of sol-gel derived sen powders using raman spectroscopy and X-ray diffractometry

Abstract

Sol-gel derived Sr_xBa_1−xNb₂O₆(SBN) powders of different chemical composition (x = 0.3 to × = 0.75) were prepared at annealing temperatures ranging from 600 °C to 1400 °C. Their structural properties were studied by Raman spectroscopy (RS) and X-ray diffractometry (XRD). The annealing temperatures for fabrication of tetragonal tungsten bronze (TTB) type SBN are found to depend on the composition. Our results suggest that the development of TTB phase SBN with × ≠ 0.5 follows two parallel reaction routes. At low temperature, the TTB phase SBN50 (x = 0.5) and excess BN or SN were formed initially. Thereafter these two phases formed the solid solution of SBN at higher annealing temperature.

Keywords:

• strontium barium niobate; sol-gel processes; powder: Raman spectroscopy and X-ray method