Abstract
Specific heat measurements on Na0.5CoO2 show that the transitions observed at 87 and 53 K in the resistivity and magnetic susceptibility are accompanied by changes in entropy, whereas the one near 20 K is not. Electron diffraction studies suggest that the 87 K transition has a structural component. The crystal structure of Na0.5CoO2, determined by powder neutron diffraction, consists of layers of edge-shared CoO6 octahedra in a triangular lattice, with Na ions occupying ordered positions in the interleaving planes. The Na ions form one-dimensional zigzag chains. Two types of Co ions are also found in chains.
Original language | English (US) |
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Pages (from-to) | 5803-5814 |
Number of pages | 12 |
Journal | Journal of Physics Condensed Matter |
Volume | 16 |
Issue number | 32 |
DOIs | |
State | Published - Aug 18 2004 |
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics