Ethylene glycol/citric acid stabilized wet chemically synthesized Y2CoNiO6, and its structural, dielectric, magnetic and electrochemical behavior

We report the synthesis of the novel double perovskite Y2CoNiO6 by an ethylene glycol and citric acid stabilized facile wet sol-gel chemical process. The material is iso-structural to the yttrium oxide cubic phase of Ia3 over bar symmetry (a = 10.5957 angstrom). The Raman vibrational modes at the wave numbers of 247, 489, 518, 566, 604, 649, 741 and 824 cm(-1) further confirmed the formation of Y2CoNiO6. The Y2CoNiO6 shows the room temperature dielectric constant of 5660 at the frequency of 500 Hz which increases further with the increase of temperature. It exhibits a predominant paramagnetic behavior with a second-order phase transition from antiferromagnetic to paramagnetic at the Neel temperature being T-FC = 51.65 K. The energy density of 19.97 W h kg(-1) at 1 A g(-1) and power density of 1324 W kg(-1) at 6 A g(-1) have been obtained. The effective charge storage is due to redox reaction of Co2+/Co3+ and Co3+/Co4+ as supported by X-ray photoelectron spectroscopy. The capacitance retainability of similar to 98.5% was achieved after 1200 charging/discharging cycles at 6 A g(-1).