Origin of Magnetoresistance in La2/3Ca1/3MnO3 in Thin Films and Bulk Materials

摘要

The present data on hole-doped manganites La1-χAχMnO3 (A=Ca, St, Ba) for the same hole concentration x varies with the route of synthesis, single crystal, thin film, polyerystal. It is shown that the transport in the system arises from quantum tunneling that depends on xz where z denotes the coordination for tunneling and depends on the microstructure.