Study of dielectric relaxation and electrical conduction mechanism in the double perovskite La2MnRuO6

• The double perovskite oxide La 2 MnRuO 6 was synthesized. • Structural and dielectric properties were investigated. • The effect of temperature was analyzed. • Two peaks are observed in the imaginary component of the impedance spectra. • The activation energy was evaluated. We have prepared the La 2 MnRuO 6 sample via the sol–gel self-combustion technique and studied the electrical modulus as well as the other dielectric properties using impedance spectroscopy. The Rietveld refinement of the powder XRD profile at ambient temperature revealed that only one phase is constituted in the elaborated sample. It crystallizes in the orthorhombic structure with Pbnm space group symmetry. The complex impedance spectroscopy was used to study the mechanism of electrical transport and dielectric relaxation. Jonscher’s universal power law controls accurately how the alternating current conductivity (AC) spectra behave. While the dielectric constant showed the effects of Maxwell-Wagner interfacial polarisation, the dielectric loss factor exhibited a frequency dependency at all the investigated values of the temperature. Two peaks can be seen in the imaginary component of the impedance Z″ spectra. The first peak is located in the low-frequencies region whereas the second peak is in the high-frequency range. A peak shift into the high-frequency region is observed when the temperature increases, which comes from the gathering at the interface of free charges with increasing temperature. Moreover, the activation energy values obtained from the conductivity were in good agreement with those obtained by the modulus.