Understanding the Charge Carrier Dynamics, Improved Dielectric Properties and Leakage Current Behaviour of NiFe1.85Dy0.15O4 with Structural Correlation

Abstract

This research explores the charge carrier dynamics of NiFe1.85Dy0.15O4 with excess amounts of Dy ions replacing the metal ions and forming an additional orthorhombic phase of DyFeO3 confirmed by the X-ray diffraction pattern of the sample and validated by Scanning electron microscopy and UV-Visible studies. Dy incorporation, in conjunction with the additional phase, has been shown to alter the structure of the inverse spinel matrix by expanding the unit cell and inducing strain. Impedance spectroscopy was used to investigate the sample’s behaviour as a circuit element, and an equivalent circuit containing resistance, capacitance, and inductance was realized to represent the sample when exposed to an alternating field. The Cole-Cole model of non-Debye relaxation was used to calculate dielectric parameters such as dielectric strength, high-frequency permittivity, shape parameters, and dielectric relaxation times. The specimen’s leakage current conduction mechanism was also systematically investigated to determine the presence of different variants of bulk and interface-limited conduction processes. This multifaceted study not only reveals the intriguing charge dynamics of NiFe1.85Dy0.15O4, which are influenced by Dy-ion incorporation and the emergence of a new phase but also extends its implications to the realm of potential applications, spurring developments in areas like novel energy storage technologies and advanced electronics.