Electrical properties optimization of rare earth Pr³⁺ ions doped Ba_1-xCa_xTi_1-yHf_yO₃ ceramics

Rare earth ions doped ferroelectric ceramics have attracted much attention because rare earth ions can effectively regulate the ferroelectric and energy storage properties of ceramics. Herein, Ba_1-xCa_xTi_1-yHf_yO₃ ceramics modified with Ca²⁺ and Hf⁴⁺ are prepared, and the effects of different Ca²⁺ and Hf⁴⁺ concentrations on the crystal structure, microstructure and electrical properties of Ba_1-xCa_xTi_1-yHf_yO₃ ceramics are investigated. Through the analysis on the ceramic structure and electrical properties, Ba_0.96Ca_0.04Ti_0.85Hf_0.15O₃ (BCTH) ceramic shows excellent comprehensive performance. Using BCTH ceramic as matrix material, the influences of different Pr³⁺ concentrations on the structure and electrical properties of the BCTH: x%Pr³⁺ ceramics are studied. Energy storage efficiency (η) gradually increases with the increase of Pr³⁺ concentration, while the energy storage density (W_d) shows a trend of first increasing and then decreasing, reaching the maximum value for x = 0.6 (W_d = 0.338 J/cm³, η = 87.86 %), which was higher than that of pure BCTH ceramics (W_d = 0.212 J/cm³, η = 78.05 %) increased by 59.43 % and 12.57 %, respectively. All the samples show good stability of energy storage temperature and frequency. After Pr³⁺ doping, the Curie transition temperature of the ceramics first increas and then decreases, and show a wider transition peak, indicating that the transition from ferroelectrics to relaxation ferroelectrics occurres. The excellent electrical properties of BCTH: x%Pr³⁺ ceramics indicate their potential application value in the field of electricity.