The methods using solid-phase synthesis or liquid precursors converted compounds of BIMEVOX family (ME is a bi- to pentavalent cation) into stable materials in a sufficiently wide concentration and temperature ranges. The crystal structure of various BIMEVOX polymorphic modifications was refined and their behavior was analyzed with respect to temperature and oxygen partial pressure. The phase transition temperature ranges were fixed. The particle size distribution was determined by means of laser diffraction and optical microscopy. The impedance measurements of BIMEVOX electroconductivity against temperature, composition, oxygen partial pressure detected the most promising compositions with respect to the absolute conductivity value and linear conductivity relationship to temperature and Po2. Different conductivity of specimens was noted with respect to method of synthesis.