J. Phys. IV France 12 (2002) Pr9-3
DOI: 10.1051/jp4:20020342

X-ray intensity fluctuation spectroscopy measurements of the charge density wave phases of NbSe ₃

M. Sutton¹, Y. Li², J.D. Brock² and R.E. Thorne<sup>3

1</sup>  Centre for the Physics of Materials and Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
²  Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, U.S.A.
³  Department of Physics, Cornell University, Ithaca, NY 14853, U.S.A.

Abstract
An introduction to X-ray Intensity Fluctuation Spectroscopy (XIFS) is given by describing its relationship to speckle from coherent sources. A brief description of the relationship of XIFS measurements to the underlying equations of motion is given. Preliminary results for the charge density wave (CDW) system NbSe ₃ are then presented. Static speckle patterns are shown for the 0) CDW peak showing that XIFS experiments are possible in this systom provided time constants are long enough. For electrical currents below threshold, a static speckle pattern is observed but for currents above threshold the speckles are smeared out showing movement of the CDW. It is also shown that above threshold, the longitudinal correlation length decreases.

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