Executive Summary : | Solid state cooling devices are being investigated as an alternative to vapor compression-based cooling technology. Different caloric responses, such as electrocaloric, magnetocaloric, and mechanocaloric (elastocaloric), are being investigated. Ferroelectric systems are a potential caloric material with significant electrocaloric (EC) response at their critical temperature (TC). However, the observed giant EC effect in most ferroelectric systems are observed at elevated temperatures or high electric fields. The flexocaloric effect based on the strain gradient can be considered as an alternate solution for temperature and field independent caloric response. This effect is the consequence of change in induced polarization caused by the large strain gradient in the lattice. The flexocaloric effect in nanoscale specimens is expected to yield a giant response. This project proposes investigating the flexocaloric effect on the flexible single crystalline ferroelectric oxide thin film fabricated on conducting substrate. The BaTi1-xSnxO3 system is chosen as the ferroelectric oxide layer. The epitaxial BSTO thin film will be deposited on a SrTiO3 substrate coated with water-soluble epitaxial Sr3Al2O6 layer by pulsed laser deposition. The BSTO will be subjected to flexocaloric studies under different strain gradient conditions generated via three-point bending method. An exclusive experimental set-up will be arranged to record the flexocaloric response. The fabricated BSTO sample will be investigated for multicaloric response by combing flexocaloric and electrocaloric phenomena. |