Influence of yttrium (Y³⁺) on structural and dielectric properties of hydrothermally processed Ba_1−xY_xTi_1−x/4O₃ materials

In this work, a series of materials composed of Ba_1−xY_xTi_1−x/4O₃ noted as BYT with x = 0, 0.025, 0.05, 0.075, 0.1 and 0.15 were prepared by hydrothermal route at 200°C for 24 h. Pressure, temperature and pH of the environment are essential factors for obtaining a pure phase. The effect of yttrium (Y³⁺) on the structural and dielectric properties of barium titanate was studied. Pure phases of the perovskite structure without secondary phases were confirmed by X-ray diffraction analysis. Raman spectroscopy analysis of the obtained samples confirms the presence of different vibration modes characteristic of the pure quadratic phase. Using a scanning electron microscope, the texture, morphology and microstructure of Ba_1−xY_xTi_1−x/4O₃ ceramics were observed. The study of dielectric properties was examined by impedance spectroscopy of dielectric measurements in the frequency range from 1 kHz to 2 MHz as a function of temperature, confirming the incorporation of yttrium and highlighting its influence on Curie temperature (T_c) and permittivity value (ε_r).