Unveiling the physicochemical properties of CaMgBiNbO ₆ double perovskite oxide

A solid-state reaction method involving high-temperature treatment at 1150 °C was employed to fabricate the CaMgBiNbO6 ceramic sample. X-ray diffraction analysis indicated the crystallisation of the specimen in various crystal symmetry phases and space groups. Scanning electron microscopy imaging revealed the polycrystalline morphology of the specimen. The UV absorption spectra exhibit an optimum wavelength of around 700 nm and a direct bandgap of approximately 2.75 eV. Dielectric and electrical measurements were conducted over the temperature range of 25–500 °C and a frequency sweep from 100 Hz to 5 MHz. The pattern observed in assessing the dielectric parameters of the sample is consistent with Koop’s theory and the Maxwell‒Wagner model. Analysis of the complex impedance and complex modulus parameters reveals that the sample undergoes a non-ideal relaxation phenomenon, unlike a Debye-like phenomenon. The role of bulk/grain and grain barrier effects on the impedance parameter is visualised by the Cole–Cole plot, and the NTCR nature is also verified. The emergence of the P–E loop suggests a ferroelectric property in the sample. These multifaceted properties of the studied CaMgBiNbO6 ceramic sample make it suitable for a variety of electronic applications.