Search for high temperature coefficient of resistance La2/3Ca1/3MnO3 polycrystalline ceramics

La2/3Ca1/3MnO3 polycrystalline ceramics were synthesized by sol–gel method. Sharp temperature coefficient of resistance (TCR) variation (with peak value up to 22 %) has been observed near the metal-insulator transition temperature TMI (273 K) for the sample sintered at 1,450 °C. This TCR value is much higher than the previously reported values for the undoped and Ag-doped La0.67Ca0.33MnO3 samples and is comparable to the optimized thin films. It was concluded that the improved physical properties of the La0.67Ca0.33MnO3 material are due to its improved microstructure and homogeneity.