Size dependent flexocaloric effect of paraelectric Ba0.67Sr0.33TiO3 nanostructures

Size dependent flexocaloric effect of paraelectric Ba0.67Sr0.33TiO3 nano-truncated pyramids was investigated based on a phenomenological thermodynamic theory. The formulas of adiabatic temperature or entropy change were deduced according to the flexoelectric effect and electrocaloric or elastocaloric effect. The results showed that flexoelectricity associated entropy change and adiabatic temperature change depend strongly on size, external stress and work temperature. The flexocaloric associated adiabatic temperature or entropy change increases with decreasing the thickness of truncated pyramids and increasing the external stress due to the increase of strain gradient. The flexocaloric entropy and adiabatic temperature changes are also enhanced with decreasing work temperature close to Tc.