Modifications in structure dependent magnetic parameters of Nd-doped Ba–Ca hexaferrites synthesized by sol gel using lemon extract as a fuel

Abstract

The Nd doped Ba–Ca ferrites, Ba0.5Ca0.5NdXFe12-XO19 (x = 0 to 0.2, Δx = 0.05) are synthetically prepared by sol gel auto-ignition method using lemon extract as the fuel. Differential thermal analysis of the thermogravimetric spectrum clearly exhibits the thermal decomposition till 1050 °C. The powder X-ray diffraction (XRD) patterns of the hexaferrites sintered at 1050 °C reveals the single-phase M-type hexaferrites possessing nano dimensions. The lattice parameters, unit cell volumes, densities, and porosities of the hexaferrites were computed from the XRD patterns. The morphology of the synthesized hexaferrites is analyzed from the digital images of the powder samples obtained by utilizing Field Emission Scanning Electron Microscope (FESEM). The relative abundance of the elements within the hexaferrites was studied by means of Energy Dispersive X-Ray Analysis (EDAX). The oxidation states and valence of the metal elements within the hexaferrites are confirmed by means of the X-ray photoelectron spectroscopy (XPS). Magnetic parameters such as coercivity, saturation magnetization, and remanence are measured by using Vibrating-Sample Magnetometer (VSM). The Mössbauer spectra of the hexaferrites are obtained to analyze the hyperfine interactions by measuring the parameters such as hyperfine field, isomer shift, quadrupole splitting, relative area, and outer line width. The varying Nd doping concentrations have modulated the magnetic parameters of Ba–Ca hexaferrites showing the control of Nd doping on magnetic behavior of the hexaferrite. The moderate saturation magnetization and high coercivity values suggest the possible use of the hexaferrites as the permanent magnets.