B-site disorder driven Griffiths-like phase and electrochemical behavior in Y<sub>2</sub>NiCrO<sub>6</sub> double perovskite
M. A. Islam, Mohasin Tarek, Md Asif Adib, M. A. Basith
Abstract
Abstract In this investigation, nanoparticles of B-site disordered Y 2 NiCrO 6 (YNCO) double perovskite were synthesized by the facile sol–gel method to evaluate their magnetic and electrochemical properties. Their crystallographic structure is monoclinic and the average size of the particles is 79±16 nm. XPS analysis indicated a mixed oxidation states of B-site transition metals Ni 2+ /Ni 3+ and Cr 2+ /Cr 3+ . The mixed valence states of Ni and Cr, along with the mixed magnetic phases of YNCO, constitute a signature of the B-site disorder. This antisite disorder contributed to the observation of a Griffiths-like phase arising from ferromagnetic short-range interactions above the magnetic transition up to the Griffiths temperature, T G = 137 K. The synthesized YNCO double perovskite demonstrated a promising behavior as an electrode material for electrochemical supercapacitors. In a three-electrode system, it displayed a specific capacitance of 270 F g −1 at a current density of 0.5 A g −1 . In a symmetric two-electrode system, YNCO exhibited a specific capacitance of 180 F g −1 at 0.5 A g −1 , alongside an energy density of 6.25 Wh kg −1 at 250 W kg −1 power density. In both cases, we employed a mild 0.5 M neutral aqueous Na 2 SO 4 solution as the electrolyte, in contrast to the typically employed corrosive and concentrated alkaline aqueous solution. The fascinating magnetic and charge storage properties of the B-site disordered YNCO double perovskite indicate its potential for use in spintronic devices and as efficient electrodes in symmetric hybrid supercapacitors.