Raman spectra of metallic and semiconducting metal hexaborides ( MB 6)

Raman spectra of divalent- and trivalent-metal hexaborides and solid solutions Gd _{1- x}Eu _xB ₆ are measured and the observed peaks are assigned to the Raman active lattice vibration modes of A_{1 g}, E_g, and F_{2 g} symmetries. On the basis of the results of these observations, the effects of the metal-boron interactions, as well as those of the boron-boron bonds, on the Raman active lattice vibration frequencies in these metal hexaborides are discussed.