The values of changes in the absorption coefficient, refractive index, and polarizability of Fe3O4 nanoparticles. (a) The dependency of changes in the absorption coefficients Δα of pure MMAS (circle) and Fe3O4 nanoparticle arrays (square and rhombus) on the intensity of radiation with wavelengths of 442 nm and 561 nm. (b) The dependency of changes in the refractive index Δn and polarizability Δα (Å3) of Fe3O4 nanoparticle arrays on the intensity of radiation with wavelengths of 442 nm (rhombus) and 561 nm (square); red dashed lines present the contribution of the thermal effect of cw radiation on the change in the refractive index (Equation 3), and blue dashed lines are theoretical approximations based on the approach of free carrier absorption (Equation 4).
Milichko et al. Nanoscale Research Letters 2013 8:317 doi:10.1186/1556-276X-8-317