The Bi₂Sn₂O₇ compound existing simultaneously in two polymorphic modifications, namely, orthorhombic and cubic, has been synthesized for the first time by solid-phase synthesis. The dielectric and electrical properties of the compound have been studied in the temperature range 100 K < T < 500 K. Anomalies in the temperature dependences of the electrical resistivity and the permittivity (imaginary and real parts) have been found at both low and high temperatures. These features are explained in terms of the model of martensitic phase transitions.

The effect of replacing manganese ions on the structural, dielectric, transport, and magnetic properties of Bi2(Sn0.9Mn0.1)2O7 has been studied and the correlation between them has been determined. Th

The correlation of the electrical, magnetic, and structural properties of B_i2(Sn_{1 − x} Cr _x )₂O₇ solid solutions has been investigated for two compositions with x = 0.05 and 0.1. The temperatures of structural phase transitions and anomalies of the electrical resistance in the vicinity of these transitions at temperatures in the range 300 K < T < 1000 K have been determined using differential scanning calorimetry. It has been found that the thermoelectric power changes sign upon the polymorphic transition. The paramagnetic Curie temperature and the chromium-ion spin have been found from the temperature dependence of the magnetic susceptibility in the range 4 K < T < 1000 K and from the field dependence of the magnetic moment in magnetic fields of up to 6 T.