Composition dependent resistivity of thick film Ni(1−x)CoxMn2O4: (0 ≤ x ≤ 1) NTC thermistors

The fritless thick film NTC thermistor of composition Ni(1−x)CoxMn2O4: (0 ≤ x ≤ 1), synthesized by oxalate co-precipitation, were prepared by screen-printing on alumina substrate. The composition dependent room temperature resistivities, thermistor constant are investigated. The relation between logarithm of resistivity (ρ) and reciprocal of absolute temperature for the prepared thick film thermistor was almost linear for all the compositions studied. The thick film thermistor with ceramic composition Ni0.6Co0.4Mn2O4 was the best with high sensitivity and lowest room temperature resistivity. Highly temperature dependent effects are also observed for temperature below 340 K.