Pr0.7Ca0.3Mn0.8Cr0.2O3 as a promising candidate for sensor and thermistor applications: investigation of TCR, SF, β, and α parameters

Abstract

Motivated by potential sensor and thermistor applications, a detailed study of the electrical behavior of Pr_0.7Ca_0.3Mn_0.8Cr_0.2O₃ (PCMCO) ceramic was carried out. Additionally, to gain deeper insight into the charge transport mechanisms in the studied material, different theoretical conduction models were employed. Indeed, DC-conductance measurements confirm the semiconducting behavior over the investigated temperature range. According to Holstein's theory, the charge transport mechanism in Pr_0.7Ca_0.3Mn_0.8Cr_0.2O₃ at elevated temperatures is primarily controlled by non-adiabatic small polaron hopping (NSPH). At low temperatures, the variable range hopping (VRH) mechanism becomes dominant. Furthermore, the temperature coefficient of resistance (TCR) was evaluated to characterize the material's thermo-resistive behavior, highlighting its potential for application in technological devices. It was found that the studied material exhibits a high TCR, reaching −20.72% K⁻¹ at 100 K, indicating its promise for use in sensor devices. By determining key thermistor parameters such as the stability factor (SF), sensitivity parameter (β), and sensitivity factor (α), Pr_0.7Ca_0.3Mn_0.8Cr_0.2O₃ is considered a promising candidate for thermistor applications. The frequency-dependent conductance spectrum, observed between 80 K and 280 K, is well described by Jonscher's power law, revealing both hopping and tunneling transport processes.