Band-gap, Urbach's energy tail and Magnetic Analysis of Cs3+-Ni2+ Doped Zinc Spinel Ferrites Nanoparticles

Over the years, spinel ferrites has attracted the attention of the research community as a result of the possibility for a variety of applications. Several attempts have been made in order to modify the optical and magnetic properties of spinel ferrites. Cs3+–Ni2+ substituted zinc spinel ferrite with chemical composition Zn1-xCsxFe2-xNixO4 (x=0.0, 0.1, 0.2) was prepared using sol-gel auto-combustion method and calcinated at 700oC for 5hrs. The UV-vis spectroscopy shows the presence of UV-cut-off at 447nm. The urbach energy tail increase with increase in Cs3+ and Ni2+ ions concentration. The band gap energy of the prepared samples was found to be in a semiconductor region. VSM analysis shows the appearance of super-exchange interaction as a result of replacement of Zn2+ by Cs3+ ions in A-site and Fe3+ by Ni2+ ions in B-site resulted in the slight decrease in the values of and . The values of is less than 0.5 which shows a single magnetic domain with uniaxial anisotropy. The values of and decrease with addition of Cs3+ and Ni2+ ions concentration. This decrease shows the anisotropic nature of the prepared samples.