DETAILED STRUCTURE OF A CHARGE-DENSITY-WAVE IN A QUENCHED RANDOM-FIELD

Using high resolution x-ray scattering, we have measured the structure of the Q1 charge-density wave in Ta-doped NbSe3. Detailed line shape analysis of the data demonstrates that two length scales are required to describe the phase-phase correlation function. Phase fluctuations with wavelengths less than a new length scale a are suppressed, and this a is identified with the amplitude coherence length. We find that ξa*=34.4±10.3. Implications for the physical mechanisms responsible for pinning are discussed. © 1994 The American Physical Society.