Mechanical energy loss in 6N-purity samples, that had been subjected to a strain of 2% and a stress of 12.6MPa, was studied by using the pulse echo technique at 10MHz. Two samples were exposed to -irradiation at room temperature or liquid N temperatures. Two dislocation relaxation peaks, B1 and B2, were found at temperatures of 179 to 169K (B1) and 221 to 210K (B2). The relaxation strengths were 8.1 x 10-4 to 2.3 x 10-5 and 1.5 x 10-3 to 1.2 x 10-4, respectively. Both the peak heights and the peak temperatures decreased as the irradiation dose was increased. The results were explained in terms of a kink-pair formation model.

W.E.Alnaser: Journal of Physics - Condensed Matter, 1996, 8[28], 5153-60