Thermal Conductivity of Manganite Perovskites: Colossal Magnetoresistance as a Lattice-Dynamics Transition

TLDR: In this article, the thermal conductivity of manganite perovskite compounds at temperatures 10,350k and fields up to 6T was investigated. But the thermal properties of mangaite pervskite are not related to quenched structural disorder, but rather to unusually large dynamic lattice distortions accompanying charge transport.

Abstract: We present the thermal conductivity ({kappa}) of several manganite perovskite compounds at temperatures 10{endash}350K and fields up to 6T. In the metallic phase, {kappa} behaves as expected for a crystalline solid. In the high-temperature insulating phase, however, d{kappa}/dT{gt}0, the behavior of an amorphous solid. Unlike amorphous solids, d{kappa}/dT{gt}0 here is related not to quenched structural disorder but rather to unusually large dynamic lattice distortions accompanying charge transport. Thus, {open_quotes}colossal magnetoresistance{close_quotes} in the manganite perovskites is characterized as a transition between regimes of different lattice dynamics. {copyright} {ital 1997} {ital The American Physical Society}