Bi12SiO20 single crystals doped with Ru, Rh, Pd, Re, Os, and Ir transition
elements were obtained. Optical absorption and optical activity were measur
ed in the visible spectral range. Strong changes were observed in transmiss
ion spectra when doping with various elements. Doping with Os and Pd causes
strong bleaching to the crystals, changes the transmission curve shoulder,
and decreases the absorption coefficient. Transmission spectra of Ru, Re,
and Ir doped crystals are shifted to the red region and the absorption coef
ficient is considerably increased. Optical rotatory power remains unchanged
by doping with Rh, Pd, Re, and Ir. It is increased negligibly by Pd doping
, considerably increased by Os doping, and strongly decreased by Ru doping.
The influence of doping elements on optical rotatory power is discussed on
the basis of the two elementary structural unit cells (BiOn polyhedra and
SiO4 tetrahedra) and of the transition energy of electrons located in their
vicinity. (C) 2001 American Institute of Physics.