Structural, magnetic, dielectric and hyperfine interaction studies of titanium (Ti4+)-substituted nickel ferrite (Ni1+xTixFe2−2xO4) nanoparticles

Abstract

Tetravalent titanium (Ti4+)-substituted nickel ferrite nanoparticles with varying composition were prepared by standard sol–gel auto-combustion method. The phase identification and nanocrystalline nature were studied through X-ray diffraction (XRD) technique. The room temperature X-ray diffraction pattern show only those planes which belong to cubic spinel structure. No extra peak other than cubic spinel structure appeared in the XRD pattern suggesting that the prepared nanoparticles possess single-phase cubic spinel structure except x = 0.4, 0.5 and 0.6. The plane (311) observed in the XRD pattern showed maximum intensity and is used to calculate the crystallite size (t). The Debye–Scherrer’s formula was used to calculate the crystallite size which was found to vary between 19 and 23 nm for varying Ti composition x. The lattice constant (a) and other structural parameters were obtained from XRD data. The lattice constant is found to be decreasesing with increase in Ti substitution. The FE-SEM images of typical samples confirmed the spherical shape morphology. The magnetic properties were studied by means of vibrating sample magnetometer and Mossbauer spectroscopy technique. All the samples exhibit a good magnetic property which decreases with Ti substitution. The saturation magnetization goes on decreasing from 43.14 (for x = 0.0) to 12.86 (for x = 0.5) which may be attributed to the decreasing A–B interaction. The Mossbauer spectrum of typical samples show sextet pattern. The Moosabauer parameters like isomer shift, quadrupole splitting, Line width etc. were obtained. The dielectric parameters such as dielectric constant, dielectric loss and dielectric loss tangent etc. were recorded using vector network analyzer.