Investigation of the Spin-Peierls transition in CuGeO3 by Raman scattering

P Lemmens, B Eisener, M Brinkmann, L.V Gasparov, G Güntherodt, P.v Dongen, W Richter, M Weiden, C Geibel, F Steglich

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Abstract

Raman experiments on the Spin-Peierls compound CuGeO3 and the substituted (Cu2−x,Znx)GeO3 and Cu(Ge1−x,GaxO3 compounds were performed in order to investigate the response of specific magnetic excitations of the one-dimensional spin-chain to spin anisotropies and substitution-induced disorder. In pure CuGeO3, in addition to normal phonon scattering which is not affected at all by the spin-peierls transition, four types of magnetic scattering features were observed. Below TSP = 14 K a singlet-triplet excitation at 30 cm−1, two-magnon scattering from 30 to 227 cm−1 and folded phonon modes at 369 and 819 cm−1 were identified. They were assigned by their temperature dependence and lineshape. For temperatures between the spin-peierls transition TSP and approsimately 100 K a broad intensity maximum centered at 300 cm−1 is observed. The temperature dependence of this intensity is similar to the behavior of lattice fluctuations recently observed in an electron diffraction study. This scattering is attributed to dynamical spin-peierls fluctuations of the weakly or non-static dimerized spin chain.
Original languageAmerican English
JournalPhysica B-condensed Matter
DOIs
StatePublished - Jun 1 1996
Externally publishedYes

Disciplines

  • Atomic, Molecular and Optical Physics
  • Physics
  • Quantum Physics
  • Condensed Matter Physics

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