An interpretation of defect production and annealing throughout stage II in dilute Ag(Cu) alloys

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Abstract
The experimental results presented in the previous paper (see ibid., vol.14, p.1379, 1984) are analysed with a simple chemical rate model for the damage production above stage I. It is assumed that the trapping of a second interstitial (i), an impurity-interstitial complex (ti), is a shallow trapping for which the resistivities are additive. Several assumptions are tried for the specific resistivity retained per trapped single interstitial, rho Ft(i). The one which leads to the best consistency yields rho Ft(i)=(160+or-10) mu Omega cm if one takes the Frenkel pair specific resistivity, rho F=200 mu Omega cm. The fact that rho Ft(i) is found to be smaller than rho F is an indication of deep trapping: a mixed dumbbell is formed, as expected. A corresponding value of the trapping radius, relative to the capture radius by a vacancy is found: Rt=rt/rv=0.2-0.3, which depends little on the temperature. The recovery spectra show that the mixed dumbbell Ag-Cu becomes mobile at about 120K. During its long-range migration it may either annihilate with a vacancy or combine with a second copper atom. The decrease in the resistivity which is found to correspond to this latter possibility leads us to assume that a dumbbell Cu-Cu can be formed, which is stable up to higher temperature.
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