Effect of iron substitution on structural, magnetic and nonlinear optical properties of zinc chromite nanoparticles

In this paper we report the structural, magnetic, nonlinear optical properties of iron substituted zinc chromite nano crystalline mixed ferrites prepared by sol-gel technique. The XRD patterns revealed the absence of any impurity peak and points to the formation of pure cubic spinel structure in all the compounds. Magnetic analysis using Vibrating Sample Magnetometer showed a change in magnetic behavior from paramagnetism to super paramagnetism as the concentration of Fe3+ ion got increased from (x = 0.00 to x = 2.00) Zero Field Cooling (ZFC) and Field Cooling (FC) was used to confirm the super paramagnetic behavior of ZnFe2O4 nanoparticles. The optical limiting properties are investigated using the open aperture z-scan technique. The optical nonlinearity increased and the material shows better optical limiting characteristics at higher iron doping concentrations. The values of optical limiting parameters of iron substituted zinc chromite nano composite makes it a potential material for the development of nonlinear optical devices with a relatively small limiting threshold. To the best of our knowledge a systematic variation of the optical limiting property with doping concentration has not been reported elsewhere.