Indentation-induced cracking and 90° domain switching pattern in barium titanate ferroelectric single crystals under different poling

Abstract

We report different domain switching patterns and indenting crack orientations under Vicker's indentation for BaTiO 3 single crystals poled in different directions. For BaTiO 3 single crystal cut and poled in [001] direction, the short indenting cracks emanate not only from the diagonals of the indentation, but also from 〈110〉 directions due to the structure mismatch along the boundaries between two adjacent domain switching zones of equivalent spreading. For single crystal cut along [100] and poled in [001] direction, we found that much shorter cracks are induced if one diagonal of the indent is put 45° (termed 45° indent), instead of 0° (termed 0° indent), away from the poling direction. It shows that 45° indents favor the formation of 90° a– c domain switching just around the indents. Driven by the structure mismatch, cracks prefer to emanate along the boundary of two adjacent domain switching zones, or from the boundary dividing the domain switch zone and non-switching zone.