Vibrational spectra of crystals of bismuth borates

The vibrational spectra of crystals of bismuth borates Bi 24 B 2 O 39 , Bi 4 B 2 O 9 , BiBO 3 , and Bi 2 B 8 O 15 were obtained for the first time, and the spectra of Bi 3 B 5 O 12 and BiB 3 O 6 crystals measured in the range 30–1600 cm −1 at room temperature were refined. The lines observed were assigned to the corresponding vibrational transitions on the basis of the theoretical group analysis and comparison of the obtained results with the vibrational spectra of borates of different composition. The complication of the structure of bismuth borates with increasing content of B 2 O 3 was traced by the example of vibrational spectra.