A comparative study on the optical limiting properties of different nano spinel ferrites with Z-scan technique

We report the optical limiting properties of five different spinel ferrites, NiFe2O4, Ni0.5Zn0.5Fe2O4, ZnFe2O4, Ni0.5Co0.5Fe2O4, and CoFe2O4 with an average particle grain size of 8 nm. The optical limiting properties are investigated using the open aperture Z-scan technique. The obtained nonlinearity fits to a two-photon like absorption process. Except for NiFe2O4, the observed nonlinearity has contributions from excited state absorption. The optical limiting response is also studied against particle size and the nonlinearity is found to increase with increasing particle size within the range of our investigations. On comparing the optical limiting properties, ZnFe2O4 is found to be a better candidate for the optical limiting applications. To the best of our knowledge, this is the first report where the optical limiting properties of spinel ferrites are compared.