Widening the temperature range and improving the linearity of CaCu3Ti4O12 ceramics for high-temperature NTC thermistor application through entropy engineering strategy

The entropy engineering strategy has been used for the first time to improve the grain boundary (GB) barrier of CaCu 3 Ti 4 O 12 (CCTO) ceramics, in order to solve its nonlinear problem at around 300 ℃ and expand its application in the field of high-temperature thermistors . To achieve this goal, we prepared (CaBaEuZnSr) 0.2 Cu 3 Ti 4 O 12 (CBEZSCT) high-entropy ceramics, and the GB spontaneous segregation properties were exploited to improve the GB resistance of CBEZSCT ceramics. The results show that the GB activation energy of CBEZSCT high-entropy ceramics (0.87 eV) is higher than that of CCTO ceramics (0.7 eV), which linearizes the resistance temperature curve and extends the application temperature limit from 300° to 750 °C. The proposed method of using a high entropy strategy to tune the GB resistance of CCTO to optimize its performance is highly effective, thus providing a new way of thinking about studying high-performance CCTO materials.