ANALYSIS OF THE OXYGEN RELAXATION SPECTRUM IN YBA2CU3O6-TEMPERATURE(XAT HIGH)

In the present work, a systematic study of the mechanical loss peak du e to the diffusion of oxygen atoms within the Cu-O planes is presented . It is observed that the height of the peak varies dramatically as th e oxygen concentration is changed. The variation of the peak height ca n be explained by a two-dimensional model. Moreover, the shape of the peak is asymmetrical and therefore cannot be interpreted by a single r elaxation mechanism. Instead, the peak can be dissociated into two bro adened Debye peaks which are controlled by an energy distribution. Thi s method of decomposition of the observed peak is more meaningful when taking into account the structural transformation which is related to the variation of the oxygen content in the specimen.