Abstract
We report the doping dependence of the ground state of -site ordered manganites below and above half doping. Energy and polarization dependence of the orbital reflection, taken by resonant soft-x-ray powder diffraction, at both Mn and O edges, provides direct evidence for orbital order at and oxygen sites and absence of Zener polaron formation. For anomalous melting of the orbital order is observed, which is coupled neither to magnetic ordering nor to a structural transition, indicating a two-dimensional character of the interactions.
- Received 5 June 2009
DOI:https://doi.org/10.1103/PhysRevLett.103.097205
©2009 American Physical Society