Europhys. Lett., 56 (2) , pp. 289-295 (2001)
X-ray scattering evidence for macroscopic strong pinning centers in the sliding CDW state ofD. 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)
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