Simulation of the effect of uniaxial compressive stress on the electromechanical properties in piezoceramics.

Ferroelectric and piezoelectric ceramics used in different electromechanical devices are often subject to various source of stresses in their working environment. Experimental results reveal that the electromechanical behavior of these materials can be tremendously altered in the presence of stress. In this paper, we present a theoretical investigation on the effect of uniaxial compressive stress on the electromechanical properties of a PZT based soft piezoceramic using Monte Carlo simulation. The dipole moment for each perovskite cell is treated as pseudo-spin and the sample is treated as a two Ç⨍Ïdimensional array of pseudo-spins oriented in four mutually perpendicular directions. Under the influence of electric field and/or stress, each dipole can undergo either 180o flipping or 90o rotation as governed by a probability. The simulation result exhibits a downward shifting of the strain-electric field butterfly loop upon the application of stress. Moreover, t! he loop area is enhanced when the magnitude of stress is below a critical value, but gradually decreases when the magnitude exceeds this value. On the other hand, both the remnant polarization and polarization-electric field hysteresis loop area monotonically decrease upon increasing the stress magnitude. These phenomena can be attributed to clamping of domain rotations. The simulation result agrees with experimental results satisfactorily.