Structural and electrical properties of Bi3TiVO9 ferroelectric ceramics

Highlights: • Ceramics with orthorhombic structure belonging to Aurivillius family. • Quality of the sample increases at high frequency as indicated from the capacitive study. • The impedance data match with the theoretical formulation. • The sample exhibits two types of conduction mechanism as indicated from AC conductivity study. Bi₃TiVO₉ (BTV), a member of Aurivillius family, has been fabricated by a mixed-oxide route at high temperature. Room temperature structural analysis using X-ray diffraction data confirms the crystallization of ceramic in the orthorhombic crystal structure. Surface morphological analysis using field-emission scanning electron microscopic (FESEM) images and elemental study with energy dispersive X-ray spectroscopy (EDX) reveal the uniform distribution of grains and compositional elements of the prepared material, respectively. Based on the temperature and frequency dependence of capacitive and resistive parameters, the electrical phenomena underlying the sample are discussed. The contribution of grain and grain boundary towards the conduction and relaxation mechanism is described by the complex impedance spectroscopy. The semi-conducting property (negative temperature coefficient of resistance (NTCR)) behavior is observed from the temperature dependent bulk resistance and J∼E characteristics of the sample. The frequency dependent ac conductivity of the system obeys the universal Jonscher's power law with conduction mechanism based on overlapping-large polaron tunneling model and correlated barrier hopping model. Measurement of room temperature hysteresis loop confirms the existence of ferroelectricity in the sample.