Probing structural and electrical properties of Ca2SnO4 with sintering temperature

Abstract

This study used the solid-state reaction method to prepare a series of Ca₂SnO₄ ceramics of the CaO–SnO₂ system in the 1300–1500 °C temperature range. The effect of sintering temperature on the phase composition, unit cell, pore densification, thermal stability, dielectric properties, and DC conductivity has been studied. Further, we have studied dielectric and electrical properties in the radio frequency range (1 KHz–2 MHz) as a function of temperature (100–600 °C). It was observed that the dielectric constant has a maximum contribution of interfacial polarization. The variation in the dielectric constant value (14.26–34.88) is small as compared to the dielectric loss/dissipation factor (0.04–10.97) at 1 kHz frequency as a function of sintering temperature. The activation energy for DC conduction for the sample sintered at 1300 °C was found to be 0.88 eV, whereas for the sample sintered at 1400 °C, it was found to be 0.74 eV. The measured activation energy lies within the expected range for the movement of oxygen ion vacancies in ceramic oxides. Therefore, the decrease in activation energy observed at elevated sintering temperatures is linked to the higher concentration of oxygen vacancies. Negligible thermal expansion up to 1500 °C makes Ca₂SnO₄ a potential candidate for low-cost substrate applications. The oxide can also be useful for thermally stable capacitors.