Coherent X-ray Scattering from Manganite Charge and Orbital Domains

TL;DR

This study uses coherent x-ray scattering to investigate charge and orbital domains in manganite materials, revealing static orbital domains in LaMnO_3 and dynamic behavior in Pr_{0.6}Ca_{0.4}MnO_3, with implications for understanding their electronic properties.

Contribution

First application of coherent x-ray scattering to simultaneously study charge and orbital domains in manganites, revealing their static or dynamic nature.

Findings

Orbital speckle pattern in LaMnO_3 is static over minutes.

Charge and orbital speckle patterns observed in Pr_{0.6}Ca_{0.4}MnO_3.

Charge order speckle patterns are static, orbital patterns show slow dynamics.

Abstract

We report coherent x-ray scattering studies of charge and orbital domains in manganite systems. The experiments were carried out on LaMnO_3 and Pr_{0.6}Ca_{0.4}MnO_3, with the incident photon energy tuned near the Mn K edge. At room temperature, the orbital speckle pattern of 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 Pr_{0.6}Ca_{0.4}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.