DIELECTRIC AND FIELD-INDUCED STRAIN BEHAVIOR OF (PB1-XBAX) ZRO3 CERAMICS

The effects of Ba2+ substitution on the dielectric properties and indu ced strain behaviour of the (Pb1-xBax) ZrO3 ceramics (0.05 less than o r equal to x less than or equal to 0.3) have been investigated as a fu nction of x. A new phase diagram of the (Pb1-xBax) ZrO3 system, indica ting the field effect on the phase transition, is also presented. As t he Ba2+ content increases, the Curie temperature decreases linearly, w hereas maximum dielectric constant increases for up to 20 mol% Ba2+ ad dition, and then decreases with further Ba2+ addition. Based on the hy steresis loops, the temperature range of the ferroelectric phase as an intermediate phase between the antiferroelectric and paraelectric pha ses, increases with increasing electric field and Ba2+ content. The fe rroelectric loops are induced at room temperature for the specimens co ntaining above 10 mol % Ba2+ by applying an electric field up to simil ar to 25 kV cm(-1). However, for the 5 mol% Ba2+-substituted specimen, no ferroelectric loop is induced, even with applied fields up to 55 k V cm(-1). The phase transition due to electric field and Ba2+ addition is also confirmed by the measurement of the field-induced longitudina l strain.