Oscillator strength and dispersive energy of dipoles in ferrite thin film

A thin film of Gd3+ doped Mn-Cr ferrite of the chemical formula MnCr0.5Gd0.02Fe1.48O4 was prepared by pulsed laser deposition from the bulk sample at room temperature. The optical absorption, transmission and reflection spectra were measured and discussed in the wavelength range from 300 to 2500 nm. The optical parameters were calculated following the single oscillator model. The optical band gap was found to be 2.75 eV, the dispersive energy of the electric dipoles was estimated using Wemple-Di Domenico relation to be 6.395 eV, while the oscillating energy of the dipole is found to be 4.997 eV. The optical dielectric constant was determined to be 3.886. The reported values could be taken as an indication to the crystal field deformation due to the large size Gd3+ ion in compensation to the physical deformation of the spinel structure.