We report coherent x-ray scattering studies of charge and orbital domains in manganite systems. The experiments were carried out on ${\mathrm{LaMnO}}_3$ and ${\mathrm{Pr}}_{0.6}{\mathrm{Ca}}_{0.4}{\mathrm{MnO}}_3,$ with the incident photon energy tuned near the Mn K edge. At room temperature, the orbital speckle pattern of ${\mathrm{LaMnO}}_3$ was observed to be constant over a timescale of at least minutes, which is indicative of static orbital domains on this timescale. For ${\mathrm{Pr}}_{0.6}{\mathrm{Ca}}_{0.4}{\mathrm{MnO}}_3,$ both charge and orbital speckle patterns were observed. The observation of the latter rules out the presence of fast orbital fluctuations, while long-time series data—on the order of several minutes—were suggestive of slow dynamic behavior. In contrast, the charge order speckle patterns were static.

• Received 18 June 2002

DOI:https://doi.org/10.1103/PhysRevB.66.134412