Phase Transitions in Solid Solutions of PbZrO₃ and PbTiO₃ (I) Small Concentrations of PbTiO₃

The dielectric, calorimetric and dilatometric measurements have been made on the solid solutions Pb(Zr-Ti)O 3 which contain small amounts of PbTiO 3 less than 10%. Besides the ordinary Curie point near 220°C, the existence of another transition, for example 140°C in Pb(Zr95-Ti5)O 3 , was confirmed. It seems reasonable to interpret these two transitions as phase changes from paraelectric state to ferroelectric one and further to antiferroelectric one. Whereas the upper transition temperature is nearly constant for these concentrations, the lower transition temperature increases with decreasing Ti concentration and both temperatures seem to coincide at pure PbZrO 3 . These results suggest that PbZrO 3 may be antiferroelectric below its Curie point 220°C.