Charge Order and Negative Thermal Expansion in V 2 OPO 4
The semivalent oxyphosphate V OPO is found to have long-range V /V charge ordering up to 605 K where a monoclinic to tetragonal structural transition and a switch from positive to negative thermal expansion are observed. V-V bonding within orbital polymer chains is proposed as the key factor in the...
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Veröffentlicht in: | Journal of the American Chemical Society 2018-01, Vol.140 (2), p.636-641 |
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Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
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Zusammenfassung: | The semivalent oxyphosphate V
OPO
is found to have long-range V
/V
charge ordering up to 605 K where a monoclinic to tetragonal structural transition and a switch from positive to negative thermal expansion are observed. V-V bonding within orbital polymer chains is proposed as the key factor in the novel switch of thermal expansion behavior, as loss of V-V bonding enables transverse oxygen motions to dominate the thermal expansion at high temperatures. Ferrimagnetic order of V
spin up and V
spin down states is observed below a magnetic ordering transition at 164 K, and susceptibility measurements evidence local spin pairing correlations to higher temperatures. |
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ISSN: | 0002-7863 1520-5126 |
DOI: | 10.1021/jacs.7b09441 |