PHASE TRANSITIONS IN THE PLZT x/85/15 SOLID SOLUTIONS

ABSTRACT

Role of a La on the nature of phase transition in the PLZT x/85/15 is compared with the PLZT compositions of lower Zr/Ti ratio. Thermal dependence of the dielectric permittivity, thermal expansion and elastic modulus reveal sequential transfer from macroscopic ferroelectric to antiferroelectric and nonpolar state, if La concentration is increased. Diffused, from frequency independent thermal dependence of dielectric permittivity for compositions in certain La concentration range above 4 at% coexist with the well expressed phase transition between paraelectric and antiferroelectric phases.

Keywords:

• Phase transitions
• dielectric permittivity
• thermal expansion
• elastic modulus
• polar microregions

ACKNOWLEDGMENTS

This research was supported by grant of Latvian Academy of Science and Austrian Academy of Science, and by the European Social Fund.