Europhys. Lett., 56 (2) , pp. 289-295 (2001)
X-ray scattering evidence for macroscopic strong pinning
centers in the sliding CDW state of
D. Rideau1, 2, P. Monceau1, R. Currat2, H. Requardt3, 4, F. Nad1, 5, J. E. Lorenzo2, 4, S. Brazovskii6, C. Detlefs4 and G. Grübel4
1 Centre de Recherches sur les Très Basses Températures, CNRS BP 166, 38042 Grenoble Cedex 9, France
2 Institut Laue-Langevin - BP 156, 38042 Grenoble Cedex 9, France
3 MPI für Metallforschung - Heisenbergstr. 1, 70569 Stuttgart, Germany
4 ESRF - BP 220, 38043 Grenoble Cedex, France
5 Institute of Radio-Engineering and Electronics - 103907 Moscow, Russia
6 LPTMS - Bât. 100, 91405 Orsay, France
(Received 26 February 2001; accepted in final form 26 July 2001)
Abstract
Using high-resolution X-ray scattering techniques, we have measured
the wave vector of the sliding charge density wave as a function of
beam position, along the length of
whiskers. We show that
structural imperfections and radiation-induced defects increase
locally the CDW pinning force, and give rise to CDW phase
distortions. Using the semi-microscopic model of
Brazovskii et al. (Phys. Rev. B, 61 (2000) 10640)
describing the normal
condensed carrier conversion,
with spatially varying parameters, we account for the experimental
spatial dependence of the CDW phase gradient near both types of
defects.
71.45.Lr - Charge-density-wave systems.
72.15.Nj - Collective modes (e.g., in one-dimensional conductors).
61.10-i - X-ray diffraction and scattering.
© EDP Sciences 2001


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