Raman and infrared spectra of KNbO3in niobate glass-ceramics

J S de Andrade, A G Pinheiro, I F Vasconcelos, J M Sasaki, J A C de Paiva, M A Valente, A S B Sombra
1999 Journal of Physics: Condensed Matter  
Potassium niobophosphate glasses and glass-ceramics of the family [xNb 2 O 5 .(50−x) P 2 O 5 .50K 2 O]:yFe 2 O 3 were studied by x-ray powder diffraction, infrared and Raman scattering spectroscopy. For the potassium-phosphate samples [50P 2 O 5 -50K 2 O] the iron oxide presents a network former behaviour, for 2 mol% of Fe 2 O 3 doping. The precipitation of crystalline K 4 Nb 6 O 17 and ferroelectric KNbO 3 crystals was confirmed by x-ray powder diffraction in the samples with x = 40 and 50
more » ... h x = 40 and 50 mol% respectively. The infrared and Raman scattering spectroscopy results suggest that the increase of the ratio Nb 2 O 5 /P 2 O 5 leads the niobium to sites of octahedral symmetry and consequently to the formation of ferroelectric KNbO 3 , as seen by x-ray diffraction analysis.
doi:10.1088/0953-8984/11/22/315 fatcat:jnr3awh6rbap7ghinpwoqj5tum