화학공학소재연구정보센터
Materials Research Bulletin, Vol.59, 125-130, 2014
Microstructure and electrical properties in W/Nb co-doped Aurivillius phase Bi4Ti3O12 piezoelectric ceramics
Aurivillius-type Bi4Ti3-xWx/2Nbx/2O12 ceramics were prepared by a conventional solid-state sintering method. The XRD patterns demonstrated that all compositions were a single three layered crystalline structure, involving a reduction of lattice distortion with an increase in W/Nb doping level. The electrical properties including dielectric, electrical conduction and piezoelectric properties were tailored by W/Nb additives. The Curie-temperature decreased, whereas the electrical resistivity drastically increased with introduction of W/Nb donor dopants. As a result, a high electric field can be applied during the poling process. The Bi4Ti2.9W0.05Nb0.05O12 ceramics exhibited optimum piezoelectric coefficient (d(33) similar to 22.8 pC/N), large remnant polarization (2P(r) similar to 26.8 mu C/cm(2) @ 200 degrees C) together with a high Curie temperature (T-c similar to 635 degrees C). Furthermore, this composition possessed a wide sintering window with outstanding piezoelectric properties. These parameters indicate that Bi4Ti2.9W0.05Nb0.05O12-based ceramic is a promising candidate for high temperature piezoelectric applications. (C) 2014 Elsevier Ltd. All rights reserved.