Role of High Sintering Temperature on Pr0.7Ca0.3MnO3 Prepared via Solid-State Reaction Method

Abstract

This study explores the effects of elevated sintering temperatures on Pr_0.7Ca_0.3MnO₃ samples prepared via the solid-state reaction method. XRD analysis shows that grain size increases with higher sintering temperature, while SEM images demonstrate significant microstructural alterations. At 1300 °C and 1400 °C, notable grain expansion, microcracks and melting indicate nucleation or recrystallisation stages, corresponding to consistent peak resistivity values of 11 Ω. Higher sintering temperatures generally enhance TCR due to improved grain connectivity. However, at 1400 °C, increased oxygen vacancies disturb electron hopping, resulting in a lower TCR. Thus, 1300 °C is identified as the optimal sintering temperature, yielding the highest TCR of 26.53 % K^-1 suitable for bolometric applications.