title: Electronic effects in manganite/insulator interfaces: interfacial enhancement of the insulating tunneling barriers.
abstract: The transport properties across perovskite oxides heterointerfaces are analyzed. Epitaxial La(2/3)Ca(1/3)MnO3/SrTiO3 (LCMO/STO) heterostructures with different STO insulating-barrier thicknesses are systematically investigated and their behavior compared with LCMO/metal junctions. Atomic force microscopy (AFM) measurements in current-sensing mode show typical features associated with tunneling conduction. Careful analysis of the I-V curves across LCMO/STO heterointerfaces, using the Simmons model in the intermediate voltage range, clearly shows the existence of an interface-induced enhancement of the tunneling barrier of about 1.6 nm on the LCMO side. These results confirm recent theoretical studies predicting electronic phase segregation and the formation of an orbital-ordered insulating phase at the manganite-insulator interface that is a result of the reduction in the number of charge carriers at the interface.
authors.affiliation: Institut de Ciència de Materials de Barcelona, CSIC, Campus universitari de Bellaterra, E- 08193 Bellaterra, Spain.
authors.forename: Lluis
authors.initials: L
authors.lastname: Balcells
authors.forename: Llibertat
authors.initials: L
authors.lastname: Abad
authors.forename: Humberto
authors.initials: H
authors.lastname: Rojas
authors.forename: Angel
authors.initials: A
authors.lastname: Perez del Pino
authors.forename: Sonia
authors.initials: S
authors.lastname: Estrade
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol
authors.forename: Francisca
authors.initials: F
authors.lastname: Peiro
authors.forename: Benjamin
authors.initials: B
authors.lastname: Martínez
mesh_terms: D006046:Gold / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission
chemical_list: D017895:Manganese Compounds; C494384:manganite; D006046:Gold