Characterization and modeling of ferroelectric materials for high pressure, high temperature applications
This dissertation focuses on the development of a deeper understanding of the pressure driven transformations in various lead zirconate titanate compositions that can be used to convert mechanical work to electrical energy and vice versa. The approach is predominantly experimental. The results are discussed in the context of thermodynamics based models and related thermodynamics based models of phase transformations.
Experimental characterization of ferroelectric materials was carried out under different loads such as hydrostatic pressure up to 1 GPa, temperature up to 175C and electric field up to ±5MV/m.
Experimental results shown that the 95--5 PZT undergoes FE--AFE--FE transformations under hysdrostatic pressure, temperature and electric field and double hysteresis loops in the AFE--FE transformation were obtained.
Results for two compositions, 95--5 PZT, and modified 52--48 PZT, are discussed in detail. Experimental results were also obtained for several related compositions and their potential use in industrial applications was assessed.