Observation of an Incommensurate Charge Density Wave in the Oxide Superconductor Ba1-xKxBiO3

Using intermediate-resolution x-ray scattering we have measured the position and width of charge density wave (CDW) satellites in a single crystal of Ba0.6K0.4BiO3. The satellites were observed to be incommensurate along a* in both the metallic and superconducting phases. Splitting of the CDW satellites along b* was observed and is indicative of a domain structure, with a linewidth determined by the domain size. Increased splitting was observed under a magnetic field of 0.8 T with an extremely long relaxation time when the field was removed.