Raman scattering and infrared absorption spectra of CuGeO3 and Y2BaNiO5 have been measured. CuGeO3is a typical inorganic spin-Peierls system with S=1/2 and Y2BaNiO5 is a recently discovered Haldane system with S=1. Two magnon excitation along the c*-axis is found for CuGeO3. Additional two-magnon excitations due to one dimensional fluctuation are observed for both system. For CuGeO3 the mode at about 30cm -1 is the soft mode due to the lattice distortion, not dug to the spin gap. The normal mode calculations for CuGeO3 show that the crystal structure is stabilized by the Ge-O frame.
ASJC Scopus subject areas
- Physics and Astronomy(all)