Structure, Raman and infrared spectroscopic properties of new nonlinear optical material Na3VO2B6O11

Abstract

In this paper we report on the structure of Na3VO2B6O11 (NVBO) single crystals which were investigated by XRD, polarized Raman spectra in the range from 10 to 1600 cm−1 and infrared spectrum (IR) in the range from 100 to 1600 cm−1. Factor group analysis has been used to study the full vibrational representation of the crystal. More than 120 phonon modes have been obtained, which are related to BO and VO vibration in the trigonal planar BO3 triangle groups and tetrahedral BO4/VO4 groups. The high frequency bands located at 1300–1415 cm−1 are assigned to stretching modes of the trigonal planar BO3 groups. Moreover, intense Raman modes located at 631 cm−1 is related to BO3 bending vibration as well. The weak band at 1158 cm−1 (A1 mode) and strong band at 431 cm−1 (A1 mode) are attributed to asymmetric stretching and bending vibration mode of tetrahedral BO4 groups respectively. The vibrational band at 765–738 cm−1 in the Raman spectra of NVBO crystal maybe related to the breathing vibration of the boroxol ring consisting of two BO4 tetrahedra. In addition, we assigned the intense band 900 (A1 mode) and 831 cm−1 (B2 mode) are relative to the v1 symmetric stretching vibration of VO4 tetrahedra. And the middle intense band at 382 (A1 mode) and 385 (A2 mode) are due to OVO vibration in VO4 tetrahedra.