STRUCTURAL AND DIELECTRIC PROPERTIES OF THE Na_(0.5)Bi_(0.5)TiO_3-NaTaO- CERAMIC SYSTEM

摘要

X-ray diffraction analysis and scanning electron microscopy have revealed that the solid solutions between Na_(0.5)Bi_(0.5)TiO_3 and NaTaO_3 form across the whole concentration range. Additionally, morphotropic phase compositions were found for samples with 5 and 15 mol% of NaTaO_3. A study of the dielectric properties showed that with increasing content of NaTaO_3 it is mainly the permittivity maximum that changes, shifting toward lower temperatures, while being depressed and broadened over a wide temperature range. Samples with morphotropic phase compositions exhibit intense dielectric relaxations in the room-temperature region, which correspond also to high values of permittivity. These characteristics make samples from the Na_(0.5)Bi_(0.5)TiO_3 and NaTaO_3 system attractive for pressure-tunable application, e.g., for pressure sensors.