Effect of Bi2O3 as sintering aid in modifying the NTC characteristics of MnCr2O4 compositions for temperature sensors

Abstract

Densification process of Mn-Cr-O negative temperature coefficient (NTC) ceramic compositions in presence of Bi2O3 as a sintering aid and also as a dopant was studied. Bi2O3 (3.8mole %) decreased the sintering temperature of the phase pure MnxCr3−xO4 compositions and obtained more than 95% of theoretical density. Electrical characteristics of the compositions were evaluated and it is found that Bi2O3 addition improved NTC properties, thus making these more suitable as temperature sensor.