Polaronic relaxation in Ca2TiMnO6 at low temperatures

Dielectric properties of Ca2TiMnO6 (CTM) were systematically investigated. Our results revealed that (1) the observed relaxation does not feature one clear Arrhenius behavior, (2) the peak intensity of the imaginary part of the complex permittivity can be well expressed by a relation similar to the Fermi–Dirac distribution function, and (3) the colossal dielectric behavior of the sample can be well understood based on the framework of universal dielectric response. These features indicate that the dielectric properties of CTM are related to polaron relaxation.

We perform detailed analysis of the peak intensity of dielectric loss. The peak intensity of dielectric loss can be well expressed by a relation similar to the Fermi–Dirac distribution function. The observed dielectric properties can be well understood based on the polaron model and suggest that the relaxation in CTM is ascribed to a polaron relaxation associated with the hopping motions of the localized carriers.Figure optionsDownload as PowerPoint slideHighlights
► Dielectric properties of Ca2TiMnO6 were systematically investigated.
► The observed relaxation does not feature one clear Arrhenius behavior.
► The dielectric properties of Ca2TiMnO6 and the conductivity are closely linked.
► The colossal dielectric behavior can be well understood based on the UDR.
► The dielectric properties of the sample are related to polaron relaxation.