A polycrystalline sample of Ba5GdTi3V7O30 was prepared using a mixed oxide method at high temperature (i.e., at 950℃). The formation of single-phase compound with orthorhombic structure at room temperature was confir...A polycrystalline sample of Ba5GdTi3V7O30 was prepared using a mixed oxide method at high temperature (i.e., at 950℃). The formation of single-phase compound with orthorhombic structure at room temperature was confirmed from preliminary X-ray diffraction study. Detailed studies of dielectric properties of Ba5GdTi3V7O30, investigated in a wide frequency range (102 - 106 Hz) at different temperatures (33℃ - 500℃) showed that these properties of the material are strongly dependent on frequency and temperature. The existence a dielectric anomaly suggests that the compound has a transition temperature at ~385℃. The nature of the variation of conductivity and value of activation energy in different regions, calculated from the temperature dependence of ac conductivity (dielectric data) suggest that the conduction process is of mixed type (i.e., ionic-polaronic and space charge generated from the oxygen ion vacancies). The ac conductivity spectrum obeys Jonscher’s universal power law.展开更多
文摘A polycrystalline sample of Ba5GdTi3V7O30 was prepared using a mixed oxide method at high temperature (i.e., at 950℃). The formation of single-phase compound with orthorhombic structure at room temperature was confirmed from preliminary X-ray diffraction study. Detailed studies of dielectric properties of Ba5GdTi3V7O30, investigated in a wide frequency range (102 - 106 Hz) at different temperatures (33℃ - 500℃) showed that these properties of the material are strongly dependent on frequency and temperature. The existence a dielectric anomaly suggests that the compound has a transition temperature at ~385℃. The nature of the variation of conductivity and value of activation energy in different regions, calculated from the temperature dependence of ac conductivity (dielectric data) suggest that the conduction process is of mixed type (i.e., ionic-polaronic and space charge generated from the oxygen ion vacancies). The ac conductivity spectrum obeys Jonscher’s universal power law.
