Structure and the nonlinearity of lithium triborate studied by Raman and infrared reflectivity spectroscopy

摘要

Raman and infrared measurements of the LiB_3O_5(LBO)crystals were completed. The experimental results shown here are more and stronger Raman lines and infrared absorption peaks, which implies that the external vibrations of the trigonal(BO_3)~3- and tetrahedral(BO_4)~5- ions, especially the former, in the six-membered boron-oxygen rings at the low wave number are strong and the internal vibrations of the(BO_4)~5- ions above 200 cm~-1 are stronger than those of the(BO_4)~3- ions if compared with the Raman spectra of BaB_2O_4 crystals.