Raman Spectroscopy Characterization of Se- Doped Bi{sub 12}SiO{sub 20} Crystals

Crystals of BSO doped with Se are successfully grown by the Czochralski method. The measured concentration of Se is 1.75x10{sup 18} cm{sup -3} and of Fe is 6.4x10{sup 18} cm{sup -3}, i.e. the concentration of Fe is significantly increased. It is assumed that the doping takes place through the replacement 3Si{sup 4+}->(Se{sup 6+}+2Fe{sup 3+}). The doping-induced shift of the Raman-active A, E and F-modes is not significant and it is concluded that the lattice distortions caused by doping are very small in BSO crystals doped with Se at low concentrations. The doping with Se at high concentration leads to occasional second phase inclusions. It is observed that all A, E and F- modes in the Raman spectrum are downshifted with 2-5 cm{sup -1}. It is concluded that the doping with Se at high concentrations follows the same mechanism as those with low concentrations but the introduced lattice distortions are more significant.