Abstract
A structural transition at 158 degrees C in Na0.63CoO2 is associated with a resistivity anomaly. Raman spectroscopy suggests a change in Na ordering at the transition and, for the first time, we have identified the nature of this rearrangement using variable temperature neutron powder diffraction. On heating, some Na ions migrate to the thermodynamically less stable (Na1) site from Na2, consistent with loss of an incommensurate superstructure. It is suggested that the change in Na order is linked to a change in the electronic band structure, which is reflected in the resistivity anomaly.
Original language | English |
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Pages (from-to) | 1342- |
Journal | Journal of Materials Chemistry |
Volume | 18 |
Issue number | 12 |
DOIs | |
Publication status | Published - 1 Jan 2008 |