Pyro-paraelectric and flexocaloric effects in barium strontium titanate: A first principles approach

摘要

Inhomogeneous strain allows the manifestation of an unexplored component of stress-driven caloric effect (flexocaloric effect) and enhanced pyroelectric performance, obtainable significantly beyond the Curie point. A peak temperature change of 1.5 K (at 289 K) was predicted from first-principles-based simulations for Ba_(0.5)Sr_(0.5)TiO_3 under the application of a strain gradient of 1.5 μm~(-1). Additionally, enhanced pyro-paraelectric coefficient (pyroelectric coefficient in paraelectric phase) and flexocaloric cooling 11 × 10~(-4) C m~(-2)K~(-1) and 1.02K, respectively, could be obtained (at 330K and 1.5 μm~(-1)). A comparative analysis with prevailing literature indicates huge untapped potential and warrants further research.