Structural, dielectric and electrocaloric properties in lead-free Zr-doped Ba0.8Ca0.2TiO3 solid solution. (July 2016)

• Record Type: Journal Article
• Authors: Asbani, B.; Gagou, Y.; Dellis, J.-L.; Lahmar, A.; Amjoud, M.; Mezzane, D.; Kutnjak, Z.; El Marssi, M.
• Is Part Of: Solid state communications. Volume 237/238(2016)
• Page Start: 49
• Page End: 54
• Publication Date: 2016-07
• Subjects: A. Ferroelectrics -- B. BCTZ ceramics -- C. Perovskite oxide -- D. Electrocaloric -- E. X-ray diffraction; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2016.04.001
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: We investigate in the present work the additional data points ( x =0.02, 0.06 and 0.08) to the previous reported paper (Asbani et al., 2015) [21] that sufficiently enrich to understand the EC properties and underlying phase diagram of the lead-free Ba0.8 Ca0.2 Ti(1− x ) Zr x O3 ( x BCTZ) system. X-ray diffraction analysis performed at room temperature, confirms a continuous tetragonal solid solution with P 4 mm (No. 99) space group that evolved to pseudo-cubic symmetry for the high Zr-content compounds. Ferroelectric and paraelectric behaviors were highlighted using P–E hysteresis data versus temperature. Phase transition was confirmed by dielectric permittivity measurements versus temperature showing a decrease of the Curie temperature when Zr-content increases. From P–E hysteresis recording the electrocaloric temperature change (Δ T ) was calculated that ranged in between 0.12 and 0.27 K and the electrocaloric responsivity ( ξ ) in 0.15 to 0.34×10 −6 K·m/V under 7.95 kV/cm applied electric field. The zero-field entropy is compared to electrocaloric isothermal entropy to estimate the extent the EC is being under-driven.