Structural and thermal stability of BIMEVOX oxygen semiconductors

The results on the structural and thermal stability of different modifications of solid solutions Bi₄V_{2 − x} Fe _x O_{11 − δ} (BIFEVOX), where x = 0.05–0.6, and Bi₄V_{2 − x} Cu _x/2Ti _x/2O_{11 − δ} (BICUTIVOX), where x = 0.025–0.50, are shown. The stability is assessed by varying the thermodynamic parameters of the medium and also the time parameters with the use of modern methods, namely, the high-temperature X-ray diffraction analysis, the differential scanning calorimetry, and the dilatometry. The γ-modification of BIFEVOX is shown to be stable in a wide range of temperatures and oxygen partial pressures.