Elastic and inelastic neutron study of CuGeO3

Abstract

Elastic and inelastic neutron scattering was used to probe the structural and magnetic properties of polycrystalline CuGeO₃. The diffraction data show that the chemical lattice remains stable in the measured temperature range 1.5 K<or=T<or=296 K. At low temperature the inelastic experiments revealed a well defined magnetic excitation at 15 meV, which persists up to T=50 K. The analysis of the spin-wave spectrum is based on a one-dimensional Heisenberg model within the spin-wave theory. On the other hand, no evidence of energy-gap opening, which would result from a dimerization of the Cu chains, could be found at low temperature.