Study of Dielectric and Electric Properties of BaTiO₃ Composites Doped with Varying Concentrations of Germanium

This study investigates the dielectric and electric properties of BaTiO₃ (Barium Titanate) composites doped with varying concentrations of germanium (Ge). The influence of Ge doping (0%, 1%, 5%, and 10%) on the frequency-dependent dielectric constant, AC conductivity, and activation energy has been systematically examined. Measurements were conducted in the frequency range of 1 kHz to 1 MHz at different temperatures (25°C, 30°C, 35°C, and 40°C). The results indicate that Ge doping enhances the electrical conductivity while reducing the activation energy, suggesting improved charge transport characteristics. The dielectric constant exhibited a decline with increasing frequency, indicating dispersion due to interfacial polarization. Additionally, Ge incorporation alters the grain boundary characteristics and charge carrier mobility, which contribute to the observed electrical enhancements. A detailed analysis of the activation energy suggests a shift in conduction mechanisms, with higher Ge concentrations promoting polaron hopping and oxygen vacancy-mediated transport. The dielectric relaxation behavior, studied through impedance spectroscopy, reveals that Ge doping affects the relaxation times and loss tangent, which are critical for optimizing capacitor and sensor applications. Furthermore, microstructural analysis indicates that Ge ions partially substitute Ti sites, leading to lattice distortions that influence the material's permittivity and electrical response. These findings provide insight into optimizing BaTiO₃-based materials for potential electronic, capacitor, and sensor applications. The study underscores the potential of Ge-doped BaTiO₃ as a tunable material for high-performance dielectric and ferroelectric devices.