P. Duran-martin et al., Study and control of the conductivity of Nb-doped Bi4Ti3O12 for high temperature piezoelectric applications, B S ESP CER, 38(6), 1999, pp. 582-586
Citations number
19
Categorie Soggetti
Material Science & Engineering
Journal title
BOLETIN DE LA SOCIEDAD ESPANOLA DE CERAMICA Y VIDRIO
Bismuth-based layered compounds have been considered during the last years
as interesting materials fur high temperature piezoelectric applications, d
ue to their stability and wide thermal range of the ferroelectric activity.
The high electrical conductivity present at high temperatures has been a d
isadvantage for the potential applications of these compounds. On Bi4Ti3O12
(BIT), different doping such as Nb5+ and W6+ were used to increase resisti
vity. It has been shown that Nb5+ doping modifies piezoelectric response, p
assing from relatively high hysteretic to linear and almost completely non-
hysteretic. In the present work, the effect of Nb5+ doping related to the c
onduction response is investigated. Studies of the I-V curves as a function
of the temperature allows us, for the first time, to measure the conductiv
ity of these compounds at room temperature (RT) and to discuss which are th
e microstructural elements that control the conductivity of the material us
ing a serial electrical model. It is shown that at temperatures between RT
and 125 degrees C the grain boundary conductivity limits the total conducti
vity. AL higher temperatures, the material conducts mainly through the bulk
of grains. Conduction type, conductivity thermal regimes and chemical comp
osition may explain the change in the piezoelectric behaviour.