Surface-Step-Terrace-Induced Anomalous Transport Properties in Highly Epitaxial La_0.67Ca_0.33MnO₃ Thin Films

Abstract

La0.67Ca0.33MnO3 thin films were epitaxially grown on miscut MgO(001) substrates by pulsed laser ablation. Electrical transport properties were studied by using an ultra high vacuum, four-probe STM system at different temperatures. Anomalous resistivity behavior and metal-insulator transition temperatures were found, both of which are highly dependent upon the miscut angle (1, 3, and 5°). These phenomena are attributed to the difference in residual strain that results from the difference in terrace widths of the vicinal surfaces.