Structural, dielectric and electrocaloric properties of (Ba 0.85 Ca 0.15 )(Ti 0.9 Zr 0.1-x Sn x )O 3 ceramics elaborated by sol-gel method S. Belkhadir a , A. Neqali a , M. Amjoud a , D. Mezzane a , A.Alimoussa a , E.Choukri a ,I.Raevski b , , Y.Gagou c,* , M. El Marssi c , Igor A. Luk'yanchuk c , Z. Kutnjak d , B. Rožič d a Laboratoire de la matière condensée et nanostructures LMCN, F.S.T.G. Université Cadi Ayyad, BP 549, Marrakech, Morocco b Research Institute of Physics and Faculty of Physics, Southern Federal University, 194 Stachki Ave., 344090, Rostov-on-Don, Russia c Laboratoire de physique de la matière condensée LPMC, Université de Picardie Jules Verne, 33 rue Saint-Leu, 80039, Amiens Cedex, France d Laboratory for calorimetry and dielectric spectroscopy, Condensed Matter Physics Department, Jozef Stefan Institute, Ljubljana, Slovenia. Abstract Ferroelectric ceramics (Ba 0.85 Ca 0.15 )(Ti 0.9 Zr 0.1-x Sn x )O 3 (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 (T C ) with increasing Sn 4+ 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. Keywords: Sol-gel, polar nanoregions, phase transition, electro-caloric.