B. Mihailova et al., Raman spectroscopy study of sillenites. II. Effect of doping on Raman spectra of Bi12TiO20, J PHYS CH S, 60(11), 1999, pp. 1829-1834
Raman spectra of single crystals of Bi12TiO20 doped with various cations, X
(X = Al, P, V, Cr, Mn, Cu, Cd, Co, W, Mo, Nd, Ag), were measured. The resu
lts show that doping of Bi12TiO20 changes the ratio between the intensities
of the transverse and the longitudinal components of the anti-symmetric Ti
-O stretching mode. Doping with Ag, Cu and V, generates an additional peak
at about 792 cm(-1) resulting from the local symmetric stretching mode of X
O4 tetrahedra. Doping with P shifts, the peaks sensitive to the geometry of
the BiOn polyhdera, which indicates that the Bi-O framework in Bi12TiO20:P
rearranges, in order to embed the second type of tetrahedral cations of a
much smaller ionic radius. (C) 1999 Elsevier Science Ltd. All rights reserv
ed.