Dielectric and impedance spectroscopy of Sm2CoIrO6 double perovskite

Polycrystalline double perovskite Sm2CoIrO6 (SMCO) ceramics have been prepared by solid state reaction to investigate dielectric properties. X-ray investigation confirms the formation of single phase with monoclinic crystal structure with space group P2(1)/n. Scanning electron microscopy (SEM) reveals the microstructural features with an average grain size of 543 nm. Dielectric, impedance and ac conductivity of the sample were studied in the temperature range 5 - 270 K and frequency range 100 Hz - 2 MHz. Temperature dependent dielectric constant reveals a giant step (similar to 10(3)) which saturates at high temperature similar to 250 K. Distribution of grain size leads to a distribution of dielectric relaxation time which has been described by Cole-Cole relaxation. Coupling of Maxwell-Wagner polarization and polaronic relaxation is evident from the impedance and ac conductivity analysis. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Polycrystalline double perovskite Sm2CoIrO6 ceramics were prepared and studied for their dielectric properties, showing a monoclinic crystal structure with an average grain size of 543 nm. The temperature-dependent dielectric constant exhibited a giant step and saturation at high temperature. The distribution of grain size led to a distribution of dielectric relaxation time.