Ferroelectric phase transition in Te-modified BaSnO3

A ferroelectric ceramic based on Te-modified BaSnO3 with a general formula BaSn1−xTexO3 (x = 0, 0.05, 0.10, 0.15) has been synthesized by a high-temperature solid-state reaction technique. Thermal analysis (DTA, TGA and DTG) was carried out to optimize calcination temperature and other experimental conditions of material formation. Preliminary structural analysis indicates that crystal structure of the material is basically cubic and remains unaffected even on Te-doping. Microstructural analysis of the sample reveals polycrystalline nature and substantial modification in surface properties of the materials on Te-doping. Detailed studies of dielectric properties of the compounds as a function of temperature showed a ferroelectric-paraelectric phase transition. It has been observed that the value of peak dielectric constant (ɛmax) and Curie temperature are strongly dependent on frequency and dopant concentration. An evidence of relaxor property has also been noticed for each concentration of the Te-dopant. Studies of electrical conductivity of the Te-doped BaSnO3 show a substantial enhancement in its value at elevated temperatures.