title: Intrinsic tunneling in phase separated manganites.
abstract: We present evidence of direct electron tunneling across intrinsic insulating regions in submicrometer wide bridges of the phase-separated ferromagnet (La,Pr,Ca)MnO3. Upon cooling below the Curie temperature, a predominantly ferromagnetic supercooled state persists where tunneling across the intrinsic tunnel barriers (ITBs) results in metastable, temperature-independent, high-resistance plateaus over a large range of temperatures. Upon application of a magnetic field, our data reveal that the ITBs are extinguished resulting in sharp, colossal, low-field resistance drops. Our results compare well to theoretical predictions of magnetic domain walls coinciding with the intrinsic insulating phase.
authors.affiliation: Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: G
authors.initials: G
authors.lastname: Singh-Bhalla
authors.forename: S
authors.initials: S
authors.lastname: Selcuk
authors.forename: T
authors.initials: T
authors.lastname: Dhakal
authors.forename: A
authors.initials: A
authors.lastname: Biswas
authors.forename: A F
authors.initials: AF
authors.lastname: Hebard