A-site deficient Ba0.975La0.0170.0085(ZrxTi0.95-x)Sn0.05O3 (x = 0.05; 0.20) ceramics (BLaZ100xTS) were synthesized using the solid-state reaction. The microstructural study revealed a high density and low porosity in the studied ceramics. Besides, grain size lower than 1.5 µm was observed in the studied compounds, which is due to the incorporation of the rare earth element (lanthanum). X-ray diffraction and Raman studies revealed that BLaZ5TS and BLaZ20TS crystallize in a perovskite-type structure with tetragonal and cubic symmetry, respectively. The dielectric study showed a normal ferroelectric-paraelectric phase transition for BLaZ5TS while a diffuse phase transition is noticed for BLaZ20TS sample. The energy-storage density and the associated energy efficiency were determined from the P-E loops versus temperature and the calculated values are comparable with results obtained on BCZT systems. Furthermore, the adiabatic temperature change ΔT was calculated through the indirect method and a relatively high value of ΔT/ΔE = 0.2 10-6 K m/V is obtained in BLaZ5TS system. The simultaneous presence of energy storage property and electrocaloric responsivity makes this system a promising environmentally friendly candidate for application in electronic devices.

Solid solutions of (1−x)BaTiO 3 -xBaSc 1/2 Nb 1/2 O 3 (BT-BSN) with x = 0.025, 0.05, 0.075, 0.1 and 0.125 were prepared by a high temperature solid-state reaction technique. The effects of the Ba(Sc 1/2 Nb 1/2 )O 3 addition on the phase composition, dielectric properties, as well as polarization-electric field (P-E) loops of the BT-BSN solid solution were investigated. The room-temperature X-ray diffraction analyses of all the ceramics revealed a perovskite phase after sintering at 1350 • C with a composition-dependent symmetry. Temperature and frequency dependence of the dielectric permittivity and losses have been explored: ceramics of compositions x ≤ 0.075 showed normal ferroelectric behavior, while ceramics with x ≥ 0.1 were of relaxor type. The degree of diffuseness and the relaxor effect increase while the transition temperature (T C or T m ) decreases when both scandium and niobium are introduced in the BaTiO 3 lattice. Ceramics of composition x = 0.125 exhibited interesting relaxor characteristics at 10 kHz: T m = 20 K, ε r = 12,000, and T m = 140 K. In addition, modeled using Vogel-Fülcher relation, this same composition showed the fitting parameters: E a = 0.0503 eV, f 0 = 1.129 × 10 14 Hz and T VF = 166.85 K.

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