PZT pyroelectric materials have been studied by many researchers because of their high pyroelectric coefficient and low dielectric constant at room temperature which enhances the figure of merits of the materials. However, sintering temperature of the commercial PZT pyroelectric materials is above 1200℃ which causes the volatilization of PbO from the PZT materials during sintering. Inhibition of PbO volatilization is required to obtain PZT pyroelectrics with good properties and to produce thick films of PZT pyroelectrics.
In this study, the low temperature sintering behavior of the PZT(94/6) ceramics with addition of $V_2O_5$ as sintering additives was investigated. By addition of 0.1 to 1 wt% $V_2O_5$, dense PZT ceramics was obtained by sintering at 900℃ for 3 h without volatilizatiion of PbO.
It has been well known that the PZT(94/6) ceramics has high pyroelectric coefficient in transition temperature by phase transition from a low temperature rhombohedral ($FR_{LT}$) to a high temperature rhombohedral ($FR_{HT}$) structure and has pyroelectric coefficient of 23 nC/㎠K at room temperature. It is necessary to move the transition temperature toward room temperature, however, in order to applicate the PZT(94/6) ceramics as an IR sensor at room temperature.
The range of transition of the PZT ceramics with addition of $V_2O_5$ was broader than that of the pure PZT and the pyroelectric coefficient of the $V_2O_5$-added PZT ceramics was increased to 50~70 nC/㎠K at room temperature.
Microstructures of the PZT ceramics were varied with the amounts of $V_2O_5$ and the methods of $V_2O_5$ addition, which also affected the pyroelectricity of PZT. The maximum pyroelectric coefficient at the transition temperature was increased, as the mean grain size was increased.
