Structural, dielectric and electrocaloric properties of (Ba0.85Ca0.15)(Ti0.9Zr0.1-xSnx)O3 ceramics elaborated by sol-gel method

• Published in: arXiv.org
• Main Authors: Belkhadir, Saad, Aziz Neqali, Mbarek Amjoud, Daoud Mezzane, Abdelhadi Alimoussa, Elhassan Choukri, Gagou, Yaovi, Raevski, Igor, Mimoun ElMarssi, Lukyanchuk, Igor, Rozic, Brigita, Kutnjak, Zdravko
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.10.2019
• Subjects: Ceramics; Curie temperature; Dielectric properties; Dielectric relaxation; Doping; Ferroelectric materials; Ferroelectricity; Physical properties; Physics - Materials Science; Raman spectra; Sol-gel processes; Temperature; Temperature profiles
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1910.02683

Ferroelectric ceramics (Ba0.85Ca0.15)(Ti0.9Zr0.1-xSnx)O3 (x=0.00, 0.02, 0.04, 0.06) were prepared by a sol-gel method. Structural investigation revealed the co-existence of tetragonal (P4mm) and orthorhombic (Pmm2) symmetries at room temperature for the undoped ceramic, while only a tetragonal structure (P4mm) was observed for the doped ceramics. Dielectric measurements indicate a dielectric relaxation process at high temperatures which is essentially related to the hopping of oxygen vacancies. Furthermore, a down shifting of the Curie temperature (TC) with increasing Sn4+ doping rate has been revealed. The temperature profiles of the Raman spectra unveiled the existence of polar nanoregions (PNRs) above the Curie temperature in all ceramics. The ferroelectric properties were found to be related to the microstructure. Electrocaloric effect was investigated in this system that revealed an electrocaloric responsivity of 0.225 10-6 K m/V for the composition with x = 0.04 Sn doping, where other remarkable physical properties were also observed.