Structure, Magnetic, and Electrical Properties of Bismuth Niobates Doped with d-Elements: VIII.1 Phase Transitions and Electrophysical Properties of Bismuth Niobate

摘要

Reversible phase transitions of bismuth niobate Bi3NbO7 have been observed: from the low-temperature cubic modification to the tetragonal one at 860°C and from the tetragonal modification to the high-temperature cubic one at 950-980°C. With increasing temperature of the cubic modification preparation, the unit cell parameter has been decreasing. Electrophysical properties of the cubic phases have matched at the frequencies below 1 kHz (up to 650 K). The specific conductivity of the tetragonal phase exceeds that of the cubic phase by no more than an order of magnitude (below 1000 K).