LOW-TEMPERATURE SINTERING AND DIELECTRIC-PROPERTIES OF PZN-BASED RELAXOR FERROELECTRICS

In this study, (1 - x)Pb1-ySry(Zn1/3Nb2/3)O3-xPbTiO3, where x = 0.00, 0.10, 0.15, 0.20 and y = 0.15, 0.20, 0.25, ceramics were fabricated by the columbite precursor method. The sintering temperature and time we re 1000 - 1150-degrees-C and 2 hours. In the 0.8Pb0.75Sr0.25 (Zn1/3 Nb 2/3)O3-0.2PbTiO3 ceramics, detrimental pyrochlore phase was completely removed when calcination temperature was higher than 900-degrees-C. T he maximum sintered density was achieved when fired at 1050-degrees-C. Dielectric constant values of the sintered/electroded disks measured at 1 kHz was rather insensitive to the sintering temperatures with typ ical value of about 6000 at room temperature. Nevertheless, the sample with higher density showed larger values than the others. Dielectric loss was lower than 5 per cent for all compositions investigated in th is study. It was especially noted that the loss was below 1 per cent w hen temperature was above 0-degree-C suggesting the possible use of th ese compositions as high permittivity dielectrics.