Abstract
We present an inelastic light scattering study of single crystalline (, and , ). A giant softening up to of the breathing mode has been observed only for the ferromagnetic insulating (FMI) samples upon cooling below the Curie temperature . With increasing Pr-doping the giant softening is strongly suppressed. This is attributed to a coupling of the breathing mode to orbital polarons, which are present in the FMI state. Moreover, the softening that persists to lowest temperature without saturation suggests a continuous, temperature-dependent evolution of orbital polarons below .
- Received 13 December 2004
DOI:https://doi.org/10.1103/PhysRevB.71.174402
©2005 American Physical Society