Ferroelectric Property and Crystal Structure of KNbO3 Based Ceramics

Autor: Masuda, Izumi, Kakimoto, Ken-Ichi, Ohsato, Hitoshi
Zdroj: Journal of Electroceramics; July 2004, Vol. 13 Issue: 1-3 p555-559, 5p
Abstrakt: Abstract Rietveld refinement analysis was carried out to obtain the knowledge on the solid solution structure of the La and Fe co-doped KNbO3 ceramics. The diffraction data was well fitted with tetragonal space group P4mm, and showed that La and Fe located at K and Nb sites in KNbO3 perovskite, respectively. The sum of both occupancy ratios agreed almost well with the doping content. Furthermore, the effects of MnO2 addition on the ferroelectric properties and crystal structure of the La and Fe co-doped KNbO3 ceramics were investigated. MnO2 addition strongly affected the ferroelectric and piezoelectric properties, because the valence of Mn ions changed from Mn4 + to some extents of Mn3 + and Mn2+, which were suggested by XAFS analysis.
Databáze: Supplemental Index