Double-exchange ferromagnetism in La(Mn{sub 1{minus}x}Co{sub x})O{sub 3}

Journal Article · Thu May 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.11072· OSTI ID:565303

Park, J; Cheong, S ^[1]; Chen, C T ^[2]

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1. Bell Laboratories, Lucent Technology, 700 Mountain Avenue, Murray Hill, New Jersey 07974 (United States)
2. Synchrotron Radiation Research Center, Hsinchu Science-based Industrial Park, Hsinchu 300, Taiwan, Republic of (China)

We have investigated the appearance of ferromagnetism in a mixture of nonferromagnets LaMnO{sub 3} and LaCoO{sub 3}, without heterovalent ion substitution in La sites. LaMn{sub 0.85}Co{sub 0.15}O{sub 3} and La{sub 0.7}Sr{sub 0.3}Mn{sub 0.8}Co{sub 0.2}O{sub 3} are studied by using x-ray-absorption and resonant photoemission spectroscopies. The results show that the dopant Co in LaMn{sub 1{minus}x}Co{sub x}O{sub 3} becomes divalent rather than expected trivalent and induces Mn{sup 3+}-Mn{sup 4+} mixed valence states. Therefore, at variance with the earlier proposal of a structure-induced Mn{sup 3+}-Mn{sup 3+} ferromagnetic coupling, the ferromagnetic state in LaMn{sub 1{minus}x}Co{sub x}O{sub 3} is consistent with the Mn{sup 3+}-Mn{sup 4+} double-exchange mechanism. {copyright} {ital 1997} {ital The American Physical Society}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 565303
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT ADDITIONS
COBALT OXIDES
DOPED MATERIALS
FERROMAGNETIC MATERIALS
LANTHANUM OXIDES
MANGANESE OXIDES
PEROVSKITES
PHOTOEMISSION
SPIN-LATTICE RELAXATION
X-RAY SPECTROSCOPY