Point contact investigations of film and interface magnetoresistance of La$_{0.7}$Sr$_{0.3}$MnO$_3$ heterostructures on Nb:SrTiO$_{3}$

Asmund Monsen; Jos E. Boschker; Per Nordblad; Roland Mathieu; Thomas Tybell; Erik Wahlström

doi:10.1016/j.jmmm.2014.08.089

paper

Point contact investigations of film and interface magnetoresistance of La $_{0.7}$ Sr $_{0.3}$ MnO $_{3}$ heterostructures on Nb:SrTiO $_{3}$

arXiv:1408.5632 · doi:10.1016/j.jmmm.2014.08.089

Abstract

STM based magnetotransport measurements of epitaxial La $_{0.7}$ Sr $_{0.3}$ MnO $_{3}$ 32 nm thick films with and without an internal LaMnO $_{3}$ layer (0-8 nm thick) grown on Nb doped SrTiO $_{3}$ are presented. The measurements reveal two types of low field magnetoresistance (LFMR) with a magnitude of $\sim 0.1 - 1.5%$ . One LFMR contribution is identified as a conventional grain boundary/domain wall scattering through the symmetric I-V characteristics, high dependence on tip placements and insensitivity to introduction of LaMnO $_{3}$ layers. The other contribution originates from the reverse biased Nb doped SrTiO $_{3}$ interface and the interface layer of La $_{0.7}$ Sr $_{0.3}$ MnO $_{3}$ . Both LFMR contributions display a field dependence indicative of a higher coercivity ( $\sim$ 200 Oe) than the bulk film. LaMnO $_{3}$ layers are found to reduce the rectifying properties of the junctions, and sub micron lateral patterning by electron beam lithography enhances the diodic properties, in accordance with a proposed transport model based on the locality of the injected current.

Point contact investigations of film and interface magnetoresistance of La0.7​Sr0.3​MnO3​ heterostructures on Nb:SrTiO3​

Abstract

References in corpus (15)

Point contact investigations of film and interface magnetoresistance of La $_{0.7}$ Sr $_{0.3}$ MnO $_{3}$ heterostructures on Nb:SrTiO $_{3}$