Sol-Gel synthesis of Ni-doped Zn-based spinel nanoferrites with structural and dielectric characterizations along with magnetic analysis

Abstract

Ni-doped zinc ferrites (NixZn1−xFe2O4, 0.00 ≤ x ≤ 0.20 in steps of 0.05) were successfully synthesized using a sol-gel self-combustion method. The addition of nickel was aimed at modifying the high-frequency dielectric and magnetic properties of zinc ferrites. Various characterizations, including XRD, FTIR, LCR, and VSM analyses, were conducted to examine the crystal structure, absorption bands, dielectric properties, and magnetic properties of the compounds. XRD patterns revealed a monophasic cubic spinel structure with a preferred (311) plane orientation. The incorporation of Ni resulted in an increased crystallite size as determined by the Scherrer equation and Williamson-Hall method. The lattice parameters and unit cell volume decreased, while X-ray density increased. FTIR transmittance spectra confirmed absorption bands associated with tetrahedral and octahedral bonding. Dielectric parameters were studied across a frequency range of 1 MHz to 3 GHz, with the Maxwell-Wagner model used to explain the observations. Both components of the complex dielectric constant decreased with increasing frequency, indicating normal dispersion behavior of spinel ferrites. The electric modulus revealed relaxation mechanisms, while AC conductivity demonstrated conduction mechanisms. Magnetic properties were characterized using M-H loops measured via VSM. Increasing the Ni concentration led to higher saturation magnetization (Ms), magnetic remanence (Mr), and coercivity (Hc). Magnetic moments and anisotropy constants were calculated based on observed values of Ms and Hc. In summary, the nickel-doped zinc ferrites exhibited notable structural, magnetic, and dielectric properties, suggesting their potential utility in microwave and high-storage magnetic devices.