Domain structure and colossal magnetoresistance of La{sub 1{minus}x}Sr{sub x}CoO{sub 3} and La{sub 1{minus}x}Ca{sub x}MnO{sub 3}

Book · Thu Oct 31 23:00:00 EST 1996

OSTI ID:392155

Wang, Z L; Berta, Y ^[1]; Zhang, J ^[2]

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1. Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering
2. Advanced Technology Materials, Inc., Danbury, CT (United States)

La{sub 1{minus}x}Sr{sub x}CoO{sub 3} (LSCO) and La{sub 1{minus}x}Ca{sub x}MnO{sub 3} (LCMO) are a class of magnetic oxides exhibiting the colossal magnetoresistance (CMR) effect. However, the CMR ratio of LSCO is much lower than that of LCMO. Microstructure studies were carried out to understand this difference. In La{sub 0.5}Sr{sub 0.5}CoO{sub 3} (LSCO), an ordered, anisotropic perovskite-type structure n-LSCO was observed. The ordered structure has a tetragonal cell with a La-Co-Sr-Co- [001] layered atom distribution along the c-axis. This new structure is intrinsic for the LSCO system and is a direct result of the lattice substitution between La and Sr. The entire film is composed of [001], [010] and [100] anisotropic domains with sizes on the order of 30--200 nm. The La{sub 0.7}Ca{sub 0.3}MnO{sub 3} (LCMO) film, however, does not exhibit a domain structure. It is concluded that the domain structure may have negative effect on the CMR ratio.

• OSTI ID: 392155
• Report Number(s): CONF-951155--; ISBN 1-55899-304-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CALCIUM OXIDES
COBALT OXIDES
CRYSTAL STRUCTURE
ELECTRON DIFFRACTION
ELECTRONIC EQUIPMENT
ENERGY-LOSS SPECTROSCOPY
EXPERIMENTAL DATA
LANTHANUM OXIDES
MAGNETORESISTANCE
MANGANESE OXIDES
MATERIALS
MICROSTRUCTURE
PEROVSKITES
STRONTIUM OXIDES
TETRAGONAL LATTICES
TRANSMISSION ELECTRON MICROSCOPY