Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1517404 | Journal of Physics and Chemistry of Solids | 2008 | 5 Pages |
Abstract
Copper (I) and silver (I) oxides crystallize with the same structure, and both show a wide range of negative thermal expansion (NTE): Cu2O contracts with temperature up to about 200Â K and then expands, while Ag2O has a NTE up to its decomposition temperature at about 450Â K. Here we report a careful temperature-dependent pair distribution function (PDF) analysis that showed that copper oxide, at about 200Â K, exhibits geometric distortions of the tetrahedral units, probably related to a change in the solid angle of the polyhedra. Silver oxide, on the other hand, showed the same distortions even at the lowest temperature measured (10Â K): structural refinements of the PDF confirmed the presence of local distortions (below 10Â Ã
) at all temperatures.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Monica Dapiaggi, HyunJeong Kim, Emil S. Božin, Simon J.L. Billinge, Gilberto Artioli,