STRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-A

The structure and electronic properties of the compound resulting from the reaction of cesium vapor with dehydrated cesium-exchanged zeolite A are reported here. Rietveld refinement of powder neutron diffraction data demonstrates the incorporation of at least two "excess" cesium atoms per...

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主要な著者: Armstrong, A, Anderson, P, Woodall, L, Edwards, P
フォーマット: Journal article
言語:English
出版事項: 1994
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author Armstrong, A
Anderson, P
Woodall, L
Edwards, P
author_facet Armstrong, A
Anderson, P
Woodall, L
Edwards, P
author_sort Armstrong, A
collection OXFORD
description The structure and electronic properties of the compound resulting from the reaction of cesium vapor with dehydrated cesium-exchanged zeolite A are reported here. Rietveld refinement of powder neutron diffraction data demonstrates the incorporation of at least two "excess" cesium atoms per primitive unit cell into the zeolite. The presence of the previously identified Cs4 linear unit was confirmed; in the present study, the different synthetic route leads to a higher concentration of the tetramer than previously reported, approaching one per primitive unit cell. Detailed structural analysis, using powder neutron diffraction, magnetic susceptibility, and electron spin resonance (ESR) studies, points to the formulation Cs42+ rather than the previously reported Cs43+. Accordingly, the compound is only weakly paramagnetic with less than 6% of the excess electrons forming localized paramagnetic centers. There are indications from the ESR g shift that this paramagnetism may originate from hole-based localized states, perhaps arising out of some partial charge fluctuation in an (otherwise) filled Cs42+ electronic band. Even for these paramagnetic centers, substantial electron-electron interactions lead to antiferromagnetic ordering below 10 K. Approximately three sodium ions per primitive unit cell resulting from incomplete ion exchange were identified; these also appear to carry some excess electron density, and there is evidence for segregation of sodium and cesium cations within the zeolite. © 1994 American Chemical Society.
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spelling oxford-uuid:b3d90f2e-21be-47d6-a8a4-dfa19cc30c8a2022-03-27T04:22:12ZSTRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-AJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b3d90f2e-21be-47d6-a8a4-dfa19cc30c8aEnglishSymplectic Elements at Oxford1994Armstrong, AAnderson, PWoodall, LEdwards, PThe structure and electronic properties of the compound resulting from the reaction of cesium vapor with dehydrated cesium-exchanged zeolite A are reported here. Rietveld refinement of powder neutron diffraction data demonstrates the incorporation of at least two "excess" cesium atoms per primitive unit cell into the zeolite. The presence of the previously identified Cs4 linear unit was confirmed; in the present study, the different synthetic route leads to a higher concentration of the tetramer than previously reported, approaching one per primitive unit cell. Detailed structural analysis, using powder neutron diffraction, magnetic susceptibility, and electron spin resonance (ESR) studies, points to the formulation Cs42+ rather than the previously reported Cs43+. Accordingly, the compound is only weakly paramagnetic with less than 6% of the excess electrons forming localized paramagnetic centers. There are indications from the ESR g shift that this paramagnetism may originate from hole-based localized states, perhaps arising out of some partial charge fluctuation in an (otherwise) filled Cs42+ electronic band. Even for these paramagnetic centers, substantial electron-electron interactions lead to antiferromagnetic ordering below 10 K. Approximately three sodium ions per primitive unit cell resulting from incomplete ion exchange were identified; these also appear to carry some excess electron density, and there is evidence for segregation of sodium and cesium cations within the zeolite. © 1994 American Chemical Society.
spellingShingle Armstrong, A
Anderson, P
Woodall, L
Edwards, P
STRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-A
title STRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-A
title_full STRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-A
title_fullStr STRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-A
title_full_unstemmed STRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-A
title_short STRUCTURE AND ELECTRONIC-PROPERTIES OF CESIUM-LOADED ZEOLITE-A
title_sort structure and electronic properties of cesium loaded zeolite a
work_keys_str_mv AT armstronga structureandelectronicpropertiesofcesiumloadedzeolitea
AT andersonp structureandelectronicpropertiesofcesiumloadedzeolitea
AT woodalll structureandelectronicpropertiesofcesiumloadedzeolitea
AT edwardsp structureandelectronicpropertiesofcesiumloadedzeolitea