Low-field magnetoresistive properties of polycrystalline and epitaxial perovskite manganite films

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.119747· OSTI ID:560602

Li, X W ^[1]; Gupta, A ^[2]; Xiao, G; Gong, G Q ^[1]

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1. Department of Physics, Brown University, Providence, Rhode Island 02912 (United States)
2. IBM Research Division, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

The low-field magnetoresistance (MR) properties of polycrystalline La{sub 0.67}Sr{sub 0.33}MnO{sub 3} and La{sub 0.67}CaO{sub 33}MnO{sub 3} thin films with different grain sizes have been investigated and compared with epitaxial films. MR as high as 15{percent} has been observed in the polycrystalline films at a field of 1500 Oe at low temperatures, whereas the MR of the epitaxial films is less than 0.3{percent} in the same field range. Based on the magnetization dependence of the MR, the current-voltage characteristics, and the temperature dependence of the resistivity, we attribute the low-field MR to spin-dependent scattering of polarized electrons at the grain boundaries which serve as pinning centers for the magnetic domain walls. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 560602
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 8 Vol. 71; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM OXIDES
FERROMAGNETIC MATERIALS
GRAIN BOUNDARIES
GRAIN SIZE
LANTHANUM OXIDES
MAGNETIZATION
MAGNETORESISTANCE
MANGANESE OXIDES
PEROVSKITES
POLYCRYSTALS
THIN FILMS