Optical properties of yttrium iron garnet irradiated with high-energy heavy ions

The damage induced in yttrium iron garnet (YIG) epilayers by high-energy heavy ions, in the electronic stopping power regime, has been monitored by optical absorption spectroscopy in the visible range. The latent track radii obtained from such data are compared with previous determinations based on saturation magnetization measurements and channelling RBS data. An optical gap shrinkage of about 1 eV is found in the disordered phase compared to the crystal. However, no variation of the refractive index is seen. These data are discussed with respect to the local atomic structure of disordered YIG. (author)