Thickness Dependent Morphological, Structural, and Magnetic Studies of Nickel Ferrite Films

Abstract

Formation and thickness variation of nickel ferrite films has been achieved by using a modified solution method. The thickness is tuned by controlling the concentration of reactant ammonia gas (NH₃). The variation in the thickness is found to result in different structural and magnetic properties of the films. The films of the thickness 129, 234, and 319 nm have been formed. The average size of crystallites is found to increase from 22.72 to 24.56 and then to 27.81 nm, respectively. At the same time, the interplanar spacing is found to decrease from 8.01 to 7.91 and then 7.84 Å, respectively. Similarly, the lattice constant decreases with the increase of the film thickness from 2.83 to 2.81 and then 2.78 Å, respectively. Studied magnetic parameters are also observed to be dependent upon the thickness of the films. All the measured three parameters, saturation magnetization, retentivity, and coercivity, are found to increase as 10.49–89.28 emu/cm³, 0.75–36.82 emu/cm³, and 20.20 to 310.21 Oe, respectively. The films show low coercive values at higher thicknesses which make them suitable for biomedical applications.