Observation of anharmonicity for copper thin film near room temperatures

The fluorescence EXAFS spectra for a copper thin film with a thickness of 3 000 Angstrom measured at 300K, 350K and 400K were analyzed by the regulariz ation method to directly obtain the radial distribution. The pair distribut ion was almost symmetric for 300K but asymmetric for 350K and 400K. This in dicates that the atoms in copper vibrate anharmonically near room temperatu res. The anharmonicity and the skewness of the asymmetric distribution incr eases as temperature increases.