Structural, magnetic and Mössbauer analysis of lanthanum and nickel doped Co2Y-type hexaferrite nanomaterial matrix synthesized by sol-gel auto-combustion technique

Abstract

Sol-gel auto-combustion technique was used to prepare the lanthanum (La3+) and nickel (Ni2+) doped Co2Y-type Sr2-yLayCo2NixFe12-xO22; x = 0.0, 0.1, 0.2, 0.3; y = 0.0, 0.01, 0.02, 0.03 nanohexaferrites materials. Synthesized nanohexaferrites were characterized by XRD, FTIR and EDS analysis. The collective XRD analysis reveals the single-phase patterns corresponding to various dopants concentration in the powder system matrix. The calculated structural - auxiliary parameters viz. Lattice constants (a and c), cell volume (Vcell), X-ray density (dx), bulk density (db) and porosity (P) have been found in range; a = 5.8798–5.8321 Å, c = 43.7316–44.7214 Å, Vcell = 1309.303–1317.304 Å3, dx = 5.014–4.987 gm/cm3, db = 3.774–3.128 gm/cm3 and P = 0.247–0.37. The XRD results were supported by FESEM and TEM images, which showed the plate-like shape of particles. Unlike irregular grains, regular platelet-like grains were composed of several crystallites with almost parallel c-axis and this is the most suitable shape for microwave absorption. Fourier-transform infrared spectroscopy (FTIR) showed the location of the ions including their respective bonds within the structure of the lattice matrix and variation of ion concentration was depicted by EDS analysis of the powder matrix. The investigation of magnetic properties was done by vibrating sample magnetometer (VSM). The saturation magnetization (Ms) and coercivity (Hc) were found to be in the range of 34.29–43.711 emu/g and 16.27–299.441 Oe, respectively. The improved values of Ms and Hc mean that these powders can be used as pre-eminent contestant materials for perpendicular recording media (PMR) applications. In addition, the synthesized Co2Y-type nanohexaferrites were characterized for the Mössbauer analysis at room temperature. The normal Zeeman (six-line patterns) splitting confirms the hexagonal phase of synthesized nanohexaferrites.