Tuning of magnetic and dielectric properties of Gallium doped hematite(α-GaxFe(2−x)O3) nanospheres

Abstract

In this work, we investigated the impact of Ga doping on the properties of α-Fe2O3 i.e. α-GaxFe(2−x)O3 (x=0.00, 0.20, 0.40, 0.60) nanospheres synthesized via novel hydrothermal technique and explored structural alterations, dielectric response, and magnetic characteristics. The hexagonal framework containing a rhombohedral lattice arrangement of α- GaxFe(2−x)O3 (x=0.00, 0.20, 0.40, and 0.60) nanoparticles has been confirmed by rigorous analysis using X-ray Diffraction (XRD) and Rietveld refinements. Nanospheres with impressive mono dispersity and an average diameter of 63 nm have been determined by scanning electron microscopy. Magnetic investigations revealed diluted antiferromagnetic spin order within Ga doped α- Fe2O3 nanoparticles marking a significant increase in the coercivity from 1595.28–2343.46 Oe (x=0.00–0.60). The observable remnant magnetization patterns illustrate the significance of Ga3+ doping in enhancing the magnetic characteristics of α-Fe2O3 attributed to the presence of uncompensated spin values between neighboring rhombohedral layers where opposite spin orientations coexist. By tracing the interactions and reversible/irreversible components, the FORC technique enabled a deeper comprehension of the magnetic response and made a substantial contribution to the interpretation of the complicated magnetic nature of the α-Ga0.20Fe1.8O3. A detailed dielectric analysis of α-GaxFe(2−x)O3 (x=0.00, 0.20, 0.40, and 0.60) nanoparticles was conducted to determine the dielectric constant (ε), dielectric loss (tanδ), ac-conductivity, complex impedance components, and the hopping probability of electron fluctuation with frequency. In the cole-cole plot for α- GaxFe(2−x)O3 (x=0.20, 0.40, and 0.60), the dominating grain boundary effect in conduction is indicated by a single semi-circle.