Exploring the structural and magnetic properties of Se-substituted NiCuZn nanospinel ferrites

Abstract

In this study, Ni 0.6 Cu 0.2 Zn 0.2 Se 3x Fe 2-4x O 4 (x x <= 0.10) nano-spinel ferrites (NCZSe3xFe2-4xO4 3x Fe 2-4x O 4 NSFs) were fabricated through a combustion synthesis employing sol-gel technique. XRD (X-ray powder diffraction) analysis confirmed the cubic spinel structure of products, crystallinity, and a single-phase composition (purity of the products). The crystallite size (DXRD) XRD ) of the products are within the range of 14-31 nm. Cubic morphology and chemical composition of the products have been verified via FE-SEM (Field Emission Scanning Electron Microscope), HR-TEM (High Resolution Transmission Electron Microscope) and EDX (Energy Dispersive X-ray Spectroscopy) and Elemental mapping analysis respectively. The magnetization properties of NCZSe3xFe2-4xO4 3x Fe 2-4x O 4 (x x <= 0.10) NSFs were also studied using vibrating sample magnetometer (VSM). Superparamagnetic behavior at room temperature (300 K, RT) and ferromagnetic behavior at low temperatures have been observed for samples. It was noted that when the level of selenium dopant grows, Ms s and Mr r are depressed. The main plausible reasons could be correlated to the changes in particle/crystallite sizes, morphology and forms of nanostructures, surface area, magnetic moments, etc. No monotonous variation has been noted for the coercivity at very low temperatures. The squareness ratios (SQRs) are much less than 0.10 at RT, confirming the stated superparamagnetic behavior at ambient temperature. The SQR values determined at T = 10 K suggest that the particles comprise multi-magnetic domain configurations.