title: Large, controllable spikes of magnetoresistance in La(2/3)Ca(1/3)MnO3/SrTiO3 superlattices.
abstract: We have investigated superlattices consisting of up to 30 epitaxial nanomultilayers (3-7 nm thick) of ferromagnetic La(2/3)Ca(1/3)MnO(3) (LCMO) and insulating SrTiO(3) (STO) hybrids. The superlattices demonstrate dramatic shifts of Curie temperature, indicating the possibility of its tunability. The metal-insulator transition (MIT) has been observed around 140 K. Below the MIT temperature, the superlattices have shown sharp drops of resistivity, facilitating the largest and sharpest magnetoresistance peaks (>2000%) ever observed in LCMO films and superlattices at low temperatures. The observed experimental results can be explained in the frame of the phase separation model in manganites with well-organized structures. The results of magnetic and transport measurements of such hybrid structures are discussed, indicating a magnetodielectric effect in STO interlayers. The magnetic and transport properties of the superlattices are shown to be technology-dependent, experiencing dimensional transitions, which enables the creation of structures with prescribed magnetoresistance characteristics for a broad range of applications.
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Fedoseev
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Pan
authors.forename: Sergey
authors.initials: S
authors.lastname: Rubanov
authors.forename: Igor A
authors.initials: IA
authors.lastname: Golovchanskiy
authors.forename: Olga V
authors.initials: OV
authors.lastname: Shcherbakova
mesh_terms: D017097:Electric Impedance; D060526:Magnetic Fields; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size