LaCrO3-based ceramics are crucial for fabricating low temperature thermistors due to their unique physical and chemical properties. However, challenges such as nonlinear electrical behaviors (temperature dependence of the resistivity deviates from the Arrhenius equation), and insufficient stability limit their application in precise temperature sensing and control. Here, we propose a high entropy strategy to design novel thermistor ceramics (La0.2Nd0.2Sm0.2Gd0.2Y0.2)CrO3−δ, which results in a widening band gap and increasing lattice distortion. These modifications lead to a significant rise in resistivity and a good linear temperature dependence of the resistivity, along with a reduced thermal hysteresis effect. The results reveal that high entropy modification crucially contributes to the improved thermal and electrical performance of LaCrO3 ceramics due to pronounced lattice distortion and band gap expansion. This study underscores the significance of entropy induced microstructural modifications, thus establishing a novel paradigm for tailoring the electronic properties of LaCrO3-based ceramics and expanding the horizons of material science in thermal sensing technologies.
Ma Panfei,Zhang Huimin,Chen Mingxing,Liu Ting,Chang Aimin,Su Zhi
Highly dense LaCrO 3 negative temperature coefficient (NTC) thermistor ceramics by low-heating solid-state method have been successfully synthesized in air ambient. The X-ray diffraction analysis has shown that both of the calcined powders and as-sintered ceramics crystallize in a perovskite structure. The relative densities of the ceramics synthesized by Cr(NO 3 ) 3 ·9H 2 O and the ceramics synthesized by CrCl 3 ·6H 2 O are 91% and 65%, respectively. The relationship between lnρ and 1000/T shows an approximate line in the measured temperature range. The values of ρ 25 and B 0/25 of the ceramics synthesized by Cr(NO 3 ) 3 ·9H 2 O and the ceramics synthesized by CrCl 3 ·6H 2 O are 424.8 Ω cm, 3252 K and 1835.9 Ω cm, 3636 K, respectively.
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