Hierarchy of defect ensembles on the surface of loaded copper

The evolution of the distribution of nanodefects formed on the surface of p olished copper foils under tensile stresses is investigated. It is found th at nanodefects form four ensembles. The energies of formation and the mean sizes of nanodefects in two consecutive ensembles differ, respectively, by a factor of three. When the concentration of nanodefects in a particular en semble reaches a thermodynamically optimum value (approximate to 5%), some of these nanodefects annihilate and the other nanodefects transform to nano defects of the following ensemble. The load applied to the sample continuou sly generates nanodefects comprising the first ensemble, which leads to per iodic oscillations of the nanodefect concentration in all four ensembles. ( C) 2001 MAIK "Nauka/Interperiodica".