Fractional substitution of Mn ions in cobalt-copper ferrite: Effect on its magnetic, dielectric and microstructural properties

Abstract

A sol–gel auto-combustion route has been employed for the preparation of Mn-substituted Co-Cu ferrite with chemical composition Co0.9Cu0.1Fe2-xMnxO4 (where x = 0.00, 0.03, 0.06, 0.09, 0.12, and 0.15). Intricate techniques like X-ray diffraction (XRD), Inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS), SEM-EDX, and TEM-SAED have been employed to achieve details of the prepared compositions. The crystalline nature and monophasic formation of the formulated compositions have been authenticated from XRD and SAED analyses, while ICP-AES results confirmed the formation of the samples as intended. The SEM and TEM studies gave an elaborate insight into sample surface morphology and particle size. XPS studies revealed the chemical states of the species present in the sample. Mössbauer analysis corroborated the oxidation state of Fe as 3+ and the ferrimagnetic nature of the prepared material. Magnetic studies presented an initial increase in saturation magnetization (Ms) with Mn-substitution followed by a decrease upon further substitution. The Curie temperature showed a steadily declining trend with Mn ion substitution. The Mn-substituted Co-Cu ferrite predominantly showed an increase in dielectric constant analogous to the pristine material.