Effect of crystallinity on the magnetoresistance in perovskite manganese oxide thin films

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.119520· OSTI ID:531729

Shreekala, R; Rajeswari, M; Ghosh, K; Goyal, A; Gu, J Y; Kwon, C; Trajanovic, Z; Boettcher, T; Greene, R L; Ramesh, R; Venkatesan, T ^[1]

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1. Department of Physics, Center for Superconductivity Research, University of Maryland, College Park, Maryland 20742 (United States)

We report our study of the effect of crystallinity on the magnetoresistance in epitaxial and polycrystalline La{sub 2/3}Ba{sub 1/3}MnO{sub 3} and La{sub 2/3}Ca{sub 1/3}MnO{sub 3} thin films. Magnetoresistance in epitaxial films exhibits field dependence and temperature dependence similar to bulk single crystals and sintered bulk ceramics. The polycrystalline films exhibit a markedly different behavior. The magnetoresistance in this case shows either a monotonic increase or saturation with decreasing temperature in contrast to that of epitaxial films in which the magnetoresistance peaks close to the ferromagnetic transition temperature. The field dependence in the polycrystalline films is also remarkably different. At low fields, we observe a sharp drop in resistance followed by a more gradual decrease at higher fields. Our data suggest that in addition to the intrinsic magnetoresistance, grain-boundary transport contributes significantly to the magnetoresistance in polycrystalline films. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 531729
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 2 Vol. 71; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM OXIDES
FERROMAGNETIC MATERIALS
GRAIN BOUNDARIES
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MAGNETORESISTANCE
MANGANESE OXIDES
MICROSTRUCTURE
POLYCRYSTALS
TEMPERATURE DEPENDENCE
THIN FILMS