Berlin 2005 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 16: Posters Correlated Electrons, Measuring Devices, Cryotechnique

TT 16.54: Poster

Samstag, 5. März 2005, 11:00–16:30, Poster TU C

A Raman study of the charge-density-wave system A_0.3MoO₃ (A=K,Rb) — •D. M. Sagar¹, D. Fausti¹, P. H. M. van Loosdrecht¹, S. Yue², C. A. Kuntscher², M. Dressel², and S. van Smaalen³ — ¹Material Science Center, University of Groningen, 9747 AG Groningen, The Netherlands — ²1. Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany — ³Laboratory of Crystallography, University of Bayreuth, 95440 Bayreuth, Germany

The Peierls instability in (quasi-)one-dimensional metals leads to the formation of a charge-density-wave ground state at reduced temperatures. The fundamental excitations of this state, phasons and amplitudons, are strongly coupled charge-lattice excitations. While the infrared-active pinned phason mode is relatively well studied by various spectroscopic techniques, less is known on the low frequency Raman-active amplitudons. We present results of a Raman study of the well known bronzes A_0.3MoO₃ (A = K,Rb), focusing not only on the amplitudon mode but also on the so-called phase phonons in the charge-density-wave state, as well as on the observed pre-transitional Peierls fluctuations in the high temperature phase. Supported by the NWO, DN-67-310, and DFG, SPP 1073.