POLARIZED RAMAN-SPECTRA OF SE CHAINS ISOLATED IN CHANNELS OF ALPO4-5 SINGLE-CRYSTAL

Polarized Raman spectra are measured for Se species incorporated into one-dimensional channels of AlPO4-5 (AFI) single crystal. The optical phonon modes of Se/AFI are observed to be shifted to higher frequencie s from that of a trigonal Se crystal, because of the loss of inter-cha in interactions in the Se/AFI. Sharp Raman signals show that the Se sp ecies is of high crystallinity. By symmetry analysis of the polarized Raman spectra, we deduce the Se species in the AFI channels to be of h elical chain structure with D-3 symmetry. Copyright (C) 1996 Elsevier Science Ltd