Experimental characterization of the Bordoni peak in copper using 10–50 MHz longitudinal ultrasonic waves

Abstract

The logarithmic decrement and its associated modulus defect were obtained in the temperature range 77–300 K, at frequencies 10–50 MHz, in a crystalline sample deformed at room temperature by 20% along (111). The well developed Bordoni peaks observed were compared with those obtained in similar samples deformed at room temperature between 3 and 10% along (111), and (110), and a general characterization of the high-frequency Bordoni peak was realized. The main characteristics of this Bordoni peaks are, firstly, that the activation energy is 0.075 eV and, secondly, that the peak width is 30% greater than a Debye peak. These experimental properties appear to be in reasonable agreement with the theoretical predictions if kink diffusion in dislocation lines is considered in the kink pair formation process.