Enhanced dielectric and electrocaloric properties in lead-free rod-like BCZT ceramics

Zouhair Hanani (1, 2) , Soukaina Merselmiz (2) , Abdelaadim Danine (3) , Nicolas Stein (3) , Daoud Mezzane (2) , M’barek Amjoud (2) , Mohammed Lahcini (2, 4) , Yaovi Gagou (5) , Matjaz Spreitzer (6) , Damjan Vengust (6) , Zdravko Kutnjak (6) , Mimoun El Marssi (5) , Igor A. Luk'Yanchuk (7, 5) , Mohamed Gouné (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 IMED-Lab - Laboratoire des Matériaux Innovants, Energie et Développement Durable [Marrakech]
3 IJL - Institut Jean Lamour
4 UM6P - Université Mohammed VI Polytechnique [Ben Guerir]
5 LPMC - Laboratoire de Physique de la Matière Condensée - UR UPJV 2081
6 IJS - Jozef Stefan Institute [Ljubljana]
7 Physics Faculty

Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) lead-free ceramics demonstrated excellent dielectric, ferroelectric, and piezoelectric properties at the morphotropic phase boundary (MPB). So far, to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics, researchers have mostly focused on the influence of spherical grain shape change. In this study, BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route. X-ray diffraction (XRD) and selected area electron diffraction (SAED) performed at room temperature confirm the crystallization of pure perovskite with tetragonal symmetry. Scanning electron microscopy (SEM) image showed that BCZT ceramics have kept the 1D rod-like grains with an average aspect ratio of about 4. Rod-like BCZT ceramics exhibit enhanced dielectric ferroelectric (ɛr = 11,906, tanδ = 0.014, Pr = 6.01 μgC/cm2, and Ec = 2.46 kV/cm), and electrocaloric properties (ΔT = 0.492 K and gZ = 0.289 (K·mm)/kV at 17 kV/cm) with respect to spherical BCZT ceramics. Therefore, rod-like BCZT lead-free ceramics have good potential to be used in solid-state refrigeration technology.

Domaines: Matériaux

Zouhair Hanani, Soukaina Merselmiz, Abdelaadim Danine, Nicolas Stein, Daoud Mezzane, et al.. Enhanced dielectric and electrocaloric properties in lead-free rod-like BCZT ceramics. Journal of Advanced Ceramics, 2020, 9 (2), pp.210-219. ⟨10.1007/s40145-020-0361-1⟩. ⟨hal-02635246⟩