Co-optimization of matrix phase and second phase for improved room-temperature TCR of (La0.6Na0.4MnO3)1−xAgx composites

Abstract

The ceramic matrix composites (La0.6Na0.4MnO3)1−xAgx ((LNMO)1−xAx) have been prepared via the sol-gel method to investigate their electrical transport property. Part of the Ag occupied the A-site of the LNMO matrix phase in the form of Ag+ ions, thus modifying crystal structure and raising the valence state of Mn ions. The remaining part of the Ag doped into (LNMO)1−xAx composites was present as a second phase and provided a channel for electron transport. Due to the combined optimization of the electrical transport property, the peak temperature coefficient of resistivity of the samples markedly increased with increasing Ag doping and reached the highest value of 16.84% K−1 at room temperature for (LNMO)0.7A0.3.