Exploring ion migration and aging stability in Mn_1.8ZnCo_0.6Fe_0.6O₄ and La_1-xSr_xMnO₃ composite ceramics for NTC thermistor application

A series of negative temperature coefficient (NTC) thermistor ceramics based on the 0.67Mn(1.8)ZnCo(0.6)Fe(0.6)O(4)-0.33La(1 )(-) xSrxMnO3 (0.2 <= x <= 0.8) system was prepared using the conventional solid-state method at 1350 degrees C. X-ray diffraction analysis indicated that the composition ceramics mainly consisted of the perovskite phase and the spinel phase. The composites had high density, and the grain size increased with the increase of Sr2+ content. The resistivity of the composites significantly decreased with the increase of Sr2+ ions. The resistivity, activation energy, and B value of the composites were in the range of 41.42-2800.80 omega center dot cm, 0.2247-0.4221 eV, and 2608-4898 K, respectively. After aging at 125 degrees C for 1000 h, the resistance drift was less than 2.5%, indicating good stability. The ceramic materials with a high B value and low resistance value were prepared and the measuring temperature range of the composition ceramic is from - 75 to 100 degrees C, which has potential applications in the monitoring industry.