Optische Eigenschaften und Elektronenbandstruktur von Europium und Barium

Optical properties of the divalent rare earth metals europium and ytterbium, obtained by transmission and reflection measurements in the spectral range 0.3-4.0 eV at room temperature, demonstrate the close relationship between these two metals and the alkaline earth metals, especially barium. The structure occurring in the real part of the conductivity σ(ω) could be assigned to optical interband transitions by means of recent energy band calculations for europium. The similarity of the experimental absorption curves of europium and barium suggests, in the spectral range considered, an almost identical band structure of the two metals and, moreover, no effect of the 4f-electrons of europium in the optical spectrum exists. © 1967 Springer-Verlag.