Enhancement in the linear electrical properties and thermal stability of chromite perovskites through entropy engineering

Abstract

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 (La_0.2Nd_0.2Sm_0.2Gd_0.2Y_0.2)CrO_3−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.