DPG Phi
Verhandlungen
Verhandlungen
DPG

Regensburg 1998 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

TT: Tiefe Temperaturen

TT 21: Postersitzung III: Spin-Peierls-Systeme, Metall-Isolator-Übergang, Lokalisierung; SL: Theorie; Quantenflüssigkeiten und -kristalle; Amorphe Materialien, Tunnelsysteme; Borcarbide, Fullerene, konventionelle SL; SL dünner Filme; Experimentiertechniken

TT 21.34: Poster

Thursday, March 26, 1998, 15:00–18:30, D

Brillouin Light Scattering on Cu1−xZnxGeO3 — •G. Els1, P.H.M. van Loosdrecht1, P. Lemmens1, H. Vonberg1, G. Güntherodt1, G.S. Uhrig2, O. Fujita3, J. Akimitsu3, G. Dhalenne4, and A. Revcolevschi412. Phys. Inst., RWTH Aachen, 52056 Aachen, Germany — 2Inst. für Theor. Phys., Universität Köln, 50937 Köln, Germany — 3Dep. of Physics, Aoyama Gakuin University, Tokyo 157, Japan — 4Laboratoire de Chimie des Solides, Université de Paris-Sud, 91405 Orsay, France

Brillouin light scattering has been performed on Cu1−xZnxGeO3 single crystals as a function of temperature (2K<T<20K), magnetic field (0T<H<6T), doping (0<x<4.5%), and polarization.

In undoped CuGeO3 a thermally activated weak shoulder is observed at roughly 18 cm−1 on the low energy side of the well-known singlet bound state (SBS) at 30 cm−1. The appearance of this shoulder indicates a novel three-magnon light scattering process between excited triplet states.

In Zn-doped CuGeO3 a different scattering process with a broad but well-defined peak shape is observed below the spin- Peierls transition TSP. The peak position is at nearly half that of the SBS and has a similar temperature dependence. Its intensity increases continuously upon cooling well below TSP in contrast to the three-magnon scattering. This new mode can be understood in terms of a bound state of a magnon and a doping-induced undimerized spin.

Work supported by DFG through SFB 341 and BMBF Fkz. 13N6586

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 1998 > Regensburg