New forms of phase segregation
Article Abstract:
Some manganese-oxide perovskites were found to show intrinsic 'colossal' magnetoresistance (CMR). CMR refers to a dramatic decrease in resistivity with applied magnetic field. Small-angle neutron scattering reveals ferromagnetic clusters of manganese atoms that occur within the paramagnetic matrix of La(sub 0.67)Ca(sub 0.33)MnO(sub 3). With the application of a magnetic field, these clusters grow and their number decreases. Moreover, between T(sub c) and 1.8T(sub c), the material shrinks on cooling less rapidly than theory predicts with a sharp return to the theoretical curve on cooling below T(sub c)=260 K.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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Oxide-ion conductors by design
Article Abstract:
It has been possible to identify a novel oxide-ion electrolyte that presents a large structural family to be investigated. It is suggested that partial substitution of oxygen for vacancies occupied by lone pairs could be a very good design strategy for identifying new intrinsic-vacancy oxide-ion conductors.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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Designing fast oxide-ion conductors based on La2Mo2O9
Article Abstract:
It has been possible to identify a family of solid oxides based on the parent compound La2Mo2O9 which shows fast oxide-ion conducting properties. This material experiences a structural transition around 580 degrees C, leading to a rise in conduction by almost two orders of magnitude.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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