RAMAN-SCATTERING ON THE SPIN-PEIERLS COMPOUND ALPHA'-NAV2O5

By means of Raman scattering, we investigated single-crystalline sampl es of the new inorganic spin-Peierls compound alpha'-NaV2O5 = 34 with T-SP = 34 K. Phonons with anomalous broad line shape indicating a stro ng spin-phonon coupling above T-SP were detected. Below T-SP several a dditional modes could be observed. Different temperature dependencies of these modes are interpreted as a first hint that low-energy modes a re related to the opening of the spin-Peierls gap observed in neutron scattering experiments while other modes are related to the lowering o f the lattice symmetry due to the spin-Peierls transition. (C) 1998 El sevier Science B.V. All rights reserved.