Spin-independent and spin-dependent conductance anisotropy in layered colossal-magnetoresistive manganite single crystals

Journal Article · Thu Apr 01 04:00:00 EST 1999 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.59.9357· OSTI ID:347058

Li, Q; Gray, K E; Mitchell, J F ^[1]

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1. Materials Sciences Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

Results are reported for the conductance anisotropies in single crystals of the layered colossal magnetoresistive manganites. Well below the magnetic ordering temperatures, the zero-field anisotropy increases from {approximately}230 for La{sub 1.24}Sr{sub 1.76}Mn{sub 2}O{sub 7} to {gt}10000 for La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7}, consistent with a {ital c}-axis antiferromagnetic ground state in the latter, while the {ital spin-independent} conductivity anisotropy only increases from {approximately}230 to {approximately}300. Significant {ital c}-axis ferromagnetic fluctuations are seen in La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7}, but no evidence is found for the recently reported two-dimensional magnetic ordering transition at higher temperatures. Direct evidence suggests that spin-orbit coupling is weaker than any other possible sources of orbital ordering. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 347058
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 14 Vol. 59; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
ANTIFERROMAGNETIC MATERIALS
FERROMAGNETISM
FLUCTUATIONS
L-S COUPLING
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LAYERS
MAGNETORESISTANCE
MANGANESE OXIDES
SPIN
STRONTIUM COMPOUNDS
STRONTIUM OXIDES