Ferroelectric precursor behavior of highly cation-ordered PbSc0.5Ta0.5O3 detected by acoustic emission: Tweed and polar nanoregions

Highly ordered ferroelectric PbSc0.5Ta0.5O3 crystals were studied by acoustic emission over a wide temperature range. Acoustic emission was found at three characteristic temperatures: 330, 409, and approximate to 600 K, which are close to those, known from the same disordered crystals, containing polar nanoregions. The microstructure in our crystals contains structural tweed rather than nanoregions. The coincidence of acoustic emission temperatures points towards a close structural relationship between nanoregions and tweed. Under electric field, these temperatures shift similar to critical end point behavior. The obtained data prove that acoustic emission detects signals in a wider parameter space than previously expected. (C) 2014 AIP Publishing LLC.