A Bi-Mn based ceramic with tunable electrical properties for high temperature NTC-thermistor application

This article presents detailed structural and electrical properties of BiMn2O5-Sillenite biphasic ceramic synthesized via solid state reaction technique. The weight percentage of BiMn2O5 and Bi25Mn2O40 are found to be 90.121 ± 1.900 and 9.878 ± 0.022, respectively. The scanning electron microscope image of the composite material that reflects the presence of polycrystalline nature having the average grain size (Gavg) 1.22 µm. The topographic grain behaviour shows the presence of high intense grains nature of the material surface. We investigated relaxation processes, ionic hopping, transport mechanisms, and semiconducting properties by studying the dielectric, conductivity, modulus, and impedance spectra over a broad frequency range (1 kHz to 1 MHz) and temperatures from 25°C to 500°C. The thermistor constant (β) is 2053.8, and the temperature coefficient of resistance (TCR) is found to be ‒0.00253 which confirms the suitable NTC properties. The NTC behaviour confirms the material is very good candidate for high-T thermistor component.