Indirect and direct electrocaloric measurements of (Ba1−xCax)(Zr0.1Ti0.9)O3 ceramics (x = 0.05, x = 0.20)

Thermal-stability of the enhanced piezoelectric, energy storage and electrocaloric properties of a lead-free BCZT ceramic

“…For eco-friendly solid-state refrigeration, BCZT ceramic demonstrated enhanced electrocaloric properties. 13,[16][17][18][19][20][21] Zhou et al 18 investigated the electrocaloric effect (ECE) in lead-free (1 À x)BZT-xBCT system under a moderate electric eld of 28 kV cm À1 and reported high ECE response of 0.56 K at x ¼ 0.6. In addition, Ben Abdessalem et al 22 studied the electrocaloric effect (ECE) in BCZT indirectly using Maxwell relation under 30 kV cm À1 and obtained DT ¼ 0.565 K around T C ¼ 119 C. Besides, Hanani et al 11 reported a signicant electrocaloric temperature change (DT) of 1.479 K with remarkable refrigerant capacity (RC) of 140.33 J kg À1 , and a high coefficient of performance (COP ¼ input power/output cooling power) 23 of 6.29 under 55 kV cm À1 .…”

Thermally-stable high energy storage performances and large electrocaloric effect over a broad temperature span in lead-free BCZT ceramic

“…7 The doping of BaTiO 3 with Ca and Zr demonstrated notable improvements in the electrical and electrocaloric properties due to the enhanced relaxor behavior of BT-based ceramics. [8][9][10][11][12] In 2009, Liu and Ren 13 reported a Pb-free ceramic with composition Ba 0.85 Ca 0.15 Zr 0.10 Ti 0.90 O 3 (BCZT), having extremely high dielectric constant and piezoelectric properties at the Morphotropic Phase Boundary (MPB). This lead-free ceramic possesses a broad frequency-dependent peak corresponding to the temperature-dependent dielectric susceptibility, lower remnant polarization, and slimmer hysteresis loops due to the relaxor ferroelectric nanodomains, which are essential for realizing extremely high energy densities and efficiencies.…”

Light-Enhanced Electrocaloric Response in Lead-Free Ferroelectric Oxide

“…In obtaining the EC parameters, the temperature-dependent polarization data are extracted from two different approaches; Method (I): polarization (P) versus electric field (E) and Method II: pyroelectric current measurements 4,6,9,25,26 . For this purpose, temperature-dependent P-E measurement from 300 to 380 K recorded on the sample at 4 Hz is shown in Fig.…”

“…The EC characteristic parameters can be expressed as Δ𝑆 = − 1 A𝛽𝜌 𝑖(𝑇)ΔE, and Δ𝑇 = − 𝑇 𝐴𝛽𝐶 𝑃 𝜌 𝑖(𝑇)ΔE 25,26 . Here, 𝑖(𝑇)  is a pyroelectric coefficient, ρ and CP are mass density and heat capacity, respectively25,26 . The ∆E = E 1 − E 2 is the difference in initial (E1) and final (E2) poling fields.…”