Absence of small lattice polarons above the Curie temperature in magnetoresistive manganites

Abstract
It is generally believed that the electrical transport in magnetoresistive manganites above TC is governed by small polarons associated with large lattice distortions. We present evidence which confirms the existence of magnetic clusters (polarons) associated with minimal lattice distortions above the Curie temperature. We take advantage of the fact that the Mössbauer spectra of the relatively large and slowly fluctuating magnetic polarons consist of incompletely collapsed magnetic component with extensive wings.