Technological modification of spinel-based CuxNi1–x–yCo2yMn2–yO4 ceramics

The peculiarities of electroceramics formation in CuxNi1–x–yCo2yMn2–yO4 (0.1⩽x⩽0.8; 0.1⩽y⩽0.9–x) system under different sintering conditions are studied by the methods of X-ray diffraction, optical microscopy, electron-probe microanalysis and electrical measurements. Structure-properties relations for these ceramic semiconducting materials, obtained at different sintering temperatures are discussed. The electrical conductivity and activation energy show strong dependence on sintering temperature. Two groups of investigated ceramics with a different character of electrical conductivity dependences on the temperature of sintering are distinguished. Obtained results are explained in the framework of the model of thermally induced cation rearrangement in octahedral and tetrahedral sites of electroceramics.