Low temperature internal friction peak in high T"c superconductors - Rodriguez, E.; Luzuriaga, J.; Nunez Regueiro, M.; Fainstein, C. (Elsevier)
We measure the internal friction Q^-^1 in YBa"2Cu"3O"7"-"x and Bi"2Sr"2CaCu"2O"8"+"x samples. At temperatures near 35K for KHz frequencies we observe an attenuation peak. In the case of YBa"2Cu"3O"7"-"x, assuming a thermally activated relaxation behaviour, we are able to show that it corresponds to the same process as other peaks observed at higher frequencies. For Bi"2Sr"2CaCu"2O"8"+"x this is not the case, and the origin of the peak, found in all the measured samples, remains unknown.
http://linkinghub.elsevier.com/retrieve/pii/0038-1098(91)90574-F
Keywords: U