The logarithmic decrement and associated modulus defect were determined at 77 to 300K, using frequencies of 10 to 50MHz, for a crystalline sample which had been deformed by 20% along <111> at room temperature. Well-developed Bordoni peaks were observed and were compared with those obtained from similar samples which had been deformed by between 3 and 10% along <111> and <110> at room temperature. The main characteristics of this Bordoni peak were that the activation energy was 0.075eV and that the peak width was 30% greater than a Debye peak. The properties appeared to be in reasonable agreement with theoretical predictions when kink diffusion in dislocation lines was accounted for in the kink-pair formation process.

Experimental Characterization of the Bordoni Peak in Copper using 10-50MHz Longitudinal Ultrasonic Waves. A.Moreno-Gobbi, J.A.Eiras: Philosophical Magazine A, 2000, 80[11], 2529-36