MOLTEN-SALT SYNTHESIS AND DIELECTRIC-PROPERTIES OF PB(FE1/2NB1/2)O-3-PB(FE1/2TA1/2)O-3 (PFN-PFT) SOLID-SOLUTIONS

Solid solutions of PFN (Pb(Fe1/2Nb1/2)O-3) and PFT (Pb(Fe1/2Ta1/2)O-3) were synthesized by a molten salt method in the Nb temperature range 800-900 degrees C. The temperatures needed to form the pure perovskite phase of PFN were lower than those needed for PFT. However, the powders synthesized at higher temperature (900 degrees C) tended to decompose during sintering at high temperatures. The particle size was not uniform and the average particle size increased with increasing amounts of PFN. The sintered samples exhibited a bi-modal grain distribution. The average grain size was found to increase with increasing Nb concentration and larger particle size of the starting powders. The Curie temperatures T-c of this solid solution system decreased with increasing amounts of PFT. Furthermore the characteristics of relaxer dielectrics became evident as the concentration of PFT increased.