LOW-ENERGY INTERBAND ABSORPTION IN BCC FE AND HCP CO

We have examined the electronic structure of bcc Fe and single-crystal hcp Co by using optical absorptivity and thermoreflectance techniques for 0.2h5 eV. The optical conductivities were calculated by Kramers-Kronig analyses. A prominent structure was observed in for Fe at 2.37 eV and a shoulder was observed near 0.8 eV; the latter structure was the dominant feature in the thermoreflectance spectrum. These were discussed in terms of minority-spin band interband absorption and spin-flip interband transitions. The anisotropic optical conductivities of hcp Co were discussed in terms of recent energy-band calculations. © 1979 The American Physical Society.