Electrical conductivity and relaxation mechanisms of nanocrystalline Ba0.75Ca0.2Cs0.05TiO3.

Ca and Cs doped barium titanate lead-free ceramic with the formula Ba 0.75 Ca 0.2 Cs 0.05 TiO 3 has been prepared by the solid-state reaction method. X-ray diffraction (XRD) confirms the crystallization of the sample in a tetragonal structure with a P 4 mm space group. The phase purity and grain morphology were evaluated using X-ray diffraction and scanning electron microscopy (SEM). The material exhibits a primary phase of Ba0.75Ca0.2Cs0.05TiO3 with a minor secondary phase of BaO 2 , and the average grain size is determined to be 1.66 μm. Using non-destructive complex impedance spectroscopy (CIS), we extensively studied the electrical behavior, including complex impedance (Z*), complex modulus (M*), electrical conductivity, and relaxation mechanisms, of Ba 0.75 Ca 0.2 Cs 0.05 TiO 3 over a wide temperature (85 K–290 K) and frequency range. The ac conductivity analysis reveals that the dominant conduction mechanism is the non-overlapping small polaron tunneling (NSPT) model. The impedance analysis indicates a single semi-circle in the real and imaginary parts, suggesting a single relaxation mechanism. Additionally, the activation energy was calculated to be approximately 0.0489 eV. These findings contribute to the understanding of the structural and electrical properties of Ba 0.75 Ca 0.2 Cs 0.05 TiO 3 , highlighting its potential applications in electronic devices such as capacitors, thermistors, and ferroelectric random access memories (FRAMs). [ABSTRACT FROM AUTHOR]