Charge ordering transition near the interface of La_1-xSr_xMnO₃ (x~1/8) films

Two clear phase transitions, an insulator to metal transition followed by a metal to insulator transition on cooling, were realized in La_1−xSr_xMnO₃ (x1∼1/8) (LSMO) thin films grown on (011) SrTiO₃ substrates due to the substrate-imposed anisotropic stain. Effects of phase transitions on the rectifying behavior of the corresponding junction LSMO/Nb:SrTiO₃ were further investigated. The paramagnetic/insulator to ferromagnetic/metal transition led to a decrease in built-in potential of the junction, while the metallic to charge/orbital ordering transition results in a growth of interfacial barrier, which could be explained by Fermi-level shifts and the gap opening/closing in LSMO films. These results indicate the occurrence of clear phase transitions in the vicinity of interface in (011)-LSMO films. © 2008 American Institute of Physics.