Dielectric and electrical characteristics of La0.5Na0.5Ga0.5V0.5O3

• Structural, micro-structural and optical properties of La0.5Na0.5Ga0.5V0.5O3 were studied.
• Dielectric properties of La0.5Na0.5Ga0.5V0.5O3 are largely dependent on temperature and frequency.
• Ferroelectric transition temperature (TcTc) of this system was obtained near 145 °C.
• La0.5Na0.5Ga0.5V0.5O3 has a high dielectric constant and a good conductivity at low and high frequency.
• Ionic conductivity and transport number of the sample was measured at room temperature.

La0.5Na0.5Ga0.5V0.5O3 (LNGVO) ceramic was prepared using a high-temperature solid-state reaction method. The structural phase, microstructure, dielectric, ferroelectric and optical properties of the material were systematically investigated. The preliminary structural analysis using x-ray diffraction (XRD) data shows the formation of the material in an orthorhombic crystal structure at room temperature. Detailed studies of dielectric and electrical properties have been carried out over a wide range of frequency (1 kHz–1 MHz) and temperature (25–450 °C) in order to elucidate the basic mechanism of the conduction and relaxation process. The dielectric characteristics show that the ceramic is a relaxor with strong diffuse phase transition and frequency dispersion. The nature of the variation of ac conductivity as a function of frequency obeys the universal power law, and confirms the existence of a hopping conduction mechanism in the material. The material also exhibits ferroelectricity at room temperature with a very low value of remnant polarization. The ionic conductivity and transport number of the ferroelectric ionic conductor were obtained with the standard experiment and calculation respectively. The material shows NTCR behavior similar to that of a semi-conductor. Similar behavior has also been observed in the study of I–V characteristics of the material.