X-ray Scattering Study of the Incommensurate Phase in Mg-doped CuGeO3
Christianson, Rebecca J. Wang, Y. J. LaMarra, S. C. Birgeneau, Robert J. Kiryukhin, V. Masuda, T. Tsukada, I. Uchinokura, K. Keimer, B.
We present results of a systematic x-ray scattering study of the effects of Mg doping on the high-field incommensurate phase ofCuGeO3. Lorentzian-squared line shapes, the changing of the first-order transition to second order, and the destruction of long-range order with infinitesimal doping are observed, consistent with random-field effects in a three-dimensional XY system. Values for the soliton width in pure and lightly doped CuGeO3 are deduced. We find that even a very small doping has a drastic effect on the shape of the lattice modulation.