Colossal negative electrocaloric effects in anti-ferroelectric PLZST bulk ferroelectrics for solid-sate refrigeration

A giant negative electro-caloric effect is present in PLZST ceramics over a wide range of temperatures at high fields for the new generation of the solid-state refrigeration process. The structural phase purity, ambiguity of phases, and coexistence of dual structural phase modulation over the substitution were identified clearly with the help of different standard models. The dielectric measurement demonstrates that the phase transition from the orthorhombic anti-ferroelectric phase (AFEO) to the tetragonal anti-ferroelectric phase (AFET) happens at 155 °C, while the phase transition from AFET to paraelectric (PE) occurs at 227 °C for PLZST( x = 0.91). The change in entropy (ΔS) and adiabatic temperature change (ΔT) was estimated at different fields from 100 to 225 kV/cm. The maximum ΔT = − 4.1 K was obtained at different electric fields over the region of phase transition anti-ferroelectric and ferroelectric phases. The estimation of the real ΔT values in the negative region compared with existing literature turns out to be good optimization for -life application of refrigeration.