Temperature dependent ferroelectric and ferroelastic behaviour of PZT wafers

A study is carried out to understand the temperature dependent non-linear behaviour of PZT wafers under electrical and mechanical loading. Experiments are conducted on PZT wafers at room and elevated temperatures under a high cyclic electric field to examine their behaviour. Experimental characterization is also extended to pure mechanical loading (uni-axial compressive stress) condition at room and elevated temperatures. A temperature dependent micro-mechanical model is proposed based on internal energy to evaluate the ferrolectric and ferroelastic behaviour of PZT wafer. The developed model is incorporated into a 3D finite element framework and numerical simulations are performed. The simulated results for electrical loading are compared with experimental observations which show a significant decrease in dielectric response at elevated temperature and it is also observed that the operating temperature influences the electrical displacement and strain along poling direction (thickness direction) under mechanical loading. A parametric study has also been conducted to understand the performance of PZT wafer in which macro-state variables such as remnant polarization, remnant strain, maximum polarization, and maximum strain are extracted and discussed as a function of temperature.