Electrocaloric behavior of Ba0.85Ca0.15Zr0.1Ti0.88Sn0.02O3 cement composites
(School of Mechanical Engineering, Galgotias University, Greater Noida, Uttar Pradesh, 201306, India)
Abstract: A thrust for looking multifunctional materials for applications in civil engineering structures has attracted interest among researchers across the globe. Cement based Ba0.85Ca0.15Zr0.1Ti0.88Sn0.02O3 (BCZT-Sn) composites were prepared for electrocaloric applications with varying BCZT-Sn to cement ratio. Hysteresis loops showed some signature of saturation in cement composites. However, loops of pure sample were saturated due to its ferroelectric nature. Furthermore, these composites were explored for the first time in solid state refrigeration technology namely electrocaloric effect (ECE). Peak electrocaloric performance shows an adiabatic temperature changes of 0.71, 0.64 and 0.50 K and isothermal entropy changes of 0.86, 0.80 and 0.65 J/(kg？K) for BCZT-Sn, 10% and 15% cement composites, respectively, under application of 0-29 kV/cm electric ？eld. The adiabatic temperature change in cement based composites is comparable with that of the BCZT-Sn ferroelectric ceramics. Furthermore, the dielectric constant (εr) of composites with different ceramic contents at room temperature reveals that dielectric constant increases with an increase in BCZT-Sn proportion in composites. These cement based BCZT-Sn composite materials may be used in solid state refrigeration as they are fairly competitive with the pristine sample.
Key words: electrocaloric behavior; cement composites; dielectric; entropy