Structural characterization of the sliding charge density wave conductor, Rb sub 0.30MoO, sub 3, by nuclear magnetic resonance.

Nuclear magnetic resonance is used to determine the electric field gradients and magnetic chemical shifts at the (sup 87Rb) sites in single crystals of Rb sub 0.30MoO sub 3 at several temperatures in the high temperature phase and in the charge- density-wave (CDW) state, below 180K. The chemical shift anisotropy is small; spectral shift and shape are dominated by electric field gradients. An analysis of spectral shape, as a function of crystal orientation, that draws upon analogy with image reconstruction from projections, gives a picture of spatial orientation, and probability distribution of field gradients caused by the CDW that agree with x-ray results except for a suggestion that a small component of CDW may be present along the crystal a-axis. A simple electroscopic model of the CDW implies that ~2 electrons per unit are responsible for the observed spectral broadening.