High-Entropy Chromates (La_0.2Nd_0.2Sm_0.2Eu_0.2M_0.2)CrO₃ (M = Dy, Ho, or Er): High-Temperature Thermistor Ceramics for Ultrawide Temperature Range Measurement

High-temperature thermistors are highly promising and cost-effective solutions for temperature sensing, and current research is focused on enhancing durability at higher temperatures and expanding applicability across broader temperature ranges. Here, a series of high-temperature thermistor ceramics based on perovskite-type chromates (La 0.2 Nd 0.2 Sm 0.2 Eu 0.2 M 0.2 )CrO 3 (M = Dy, Ho, or Er) with high entropy features are proposed. Our investigations reveal exceptional characteristics in terms of sintering densities, maximum applicable temperatures, applicable temperature ranges, and aging properties for these ceramics, favoring the fabrication of high-temperature thermistors with an ultrawide applicable temperature range of 25–1500 °C and a long lifespan. Another discovery lies in the correlation between the structural and electrical stability of chromates and the total energy variation of their supercells obtained through ab initio molecular dynamics simulations at elevated temperatures. This reveals the deterioration of electrical stability in perovskite-type chromate ceramics at high temperatures from a perspective, emphasizing that the primary cause is structural instability rather than the previously held notion of oxidation mechanisms.