High-temperature plastic deformation of ⟨ 110 ⟩ -oriented BaTiO3 single crystals

Abstract

BaTiO3 single crystals were deformed in compression along the ⟨ 110 ⟩ crystal axis to study the plastic deformability and dislocation structures at high temperatures under different loading conditions. The yield strength is determined from stress–strain curves under strain rate control, load control, strain rate cycling tests, and under step-wise loading conditions to elucidate the impact of measurement approach in yield strength behavior. A comparison between the chosen methods based on stress-dependent strain rate plots indicates that load control measurements are a suitable alternative to the commonly used strain rate-control experiments in metals. This allows avoiding overloading and providing an estimate of the overall achievable strain rates in a ceramic. Activation energies and activation volumes in the temperature range of 1100–1170 °C indicate a similar mechanical deformation behavior to SrTiO3. Graphical abstract: [Figure not available: see fulltext.]