Third- and fifth-order susceptibilities of cobalt oxide nanoparticles dispersed in n-heptane

We investigated the nonlinear response of Co3O4 nanoparticles (NPs) dissolved in liquid n-heptane. The third- and fifth-order susceptibilities were measured using the Z-scan technique in experiments made with the second harmonic of an Nd: YAG laser (532 nm, 80 ps, 7 Hz). The nonlinear optical response of the colloidal system and its dependence with the NPs filling fraction were measured and theoretically described. The analysis of the results using the Maxwell–Garnet model provided a value for the Co3O4 NPs susceptibility.