The ferroelastic phase transition and non-180° domain switching in La-modified lead zirconate titanate ferroelectric ceramics

Abstract

The ferroelastic phase transition and shape memory effect in La-modified leadzirconate titanate ferroelectric ceramics are demonstrated directly throughthe temperature-dependent macroscopic recoverable strain measured in athree-point bending configuration. X-ray diffraction measurements reveal that non-180° domain switching occurs in the mechanically poled sample in two differentways at the bottom and top of the sample which have been under tensileand compressive stresses, respectively. The calculated fraction of non-180° switched domains in the poled sample increases nonlinearly with the applied force andshows a saturation trend, which is consistent with the nonlinear behavior of the remnantstrain. This study confirms that the mechanical stress applied upon cooling ferroelectricceramics from the paraelectric to the ferroelectric phase can easily activate ferroelasticdomain switching and give rise to preferred domain orientation and consequent macroscopicremnant strain which results in a history effect and shape memory effect via the ferroelasticphase transition.