Chemical etching and thickness effects on the resistive property of La 2/3Ca 1/3MnO 3 films

Abstract

Effects of chemical etching and thickness on the transport property of La 2/3Ca 1/3MnO 3 films are experimentally studied. Chemical etching produces a decrease of the metal–insulator transition from T p=263 to 235 K in addition to increasing the overall resistance of the film. Further etching does not change T p while leads to a new resistive transitions at ∼150 K. In contrast, film thickness influences the resistive behavior of the films strongly below 40 nm, resulting in a sharp drop of T p and a steep increase of the resistivity with the decrease of thickness. Reducing film thickness and chemical etching produce similar effects except for that the latter thins the film unevenly, which causes the occurrence of multi-resistive transitions. No visible effects associated with the enhanced surface roughness due to chemical etching are observed.