Decoupling of defect and short-range order contributions to resistivity recovery measurements in binary alloys

We report a new and improved approach that uses low-temperature resistivity recovery measurements to study the defect kinetics in metallic binary alloys. This method is able to decouple the effect related to the irradiation defect contribution to the resistivity from that of the short-range order, which is enhanced by the free migration of defects. This approach can provide reliable experimental data which are more suitable for comparisons with current computational models. Furthermore, the difference in this method with respect to the classical one is that our method gives information concerning the role of vacancies and interstitials on short-range order. The method is applied to a model alloy Fe-5%Cr, of interest for fusion applications, where short-range order effects have been previously found to play a role.

Figure 1

Fe-5%Cr samples irradiated with 5 MeV protons. Comparison of experimental RR curves with () and without () SRO effects after preirradiation at 400 K.

Figure 2

Differential RR curves of classic RR () and pre-$\mathrm{Irr}+\mathrm{classic}$ () RR samples.

Figure 3

Mössbauer spectra of a Fe-5% Cr 35 $\mu \mathrm{m}$ sample measured at room temperature. The red sextet refers to the pure Fe phase, green corresponds to Fe with one Cr in the 1NN, and blue corresponds to Fe having one Cr in 1NN and one Cr in 2NN. (O) is the spectrum of the “as-received” sample, (I) is the sample after 400 K pre-Irr up to a dose of $240\times {10}^{-6}$ dpa, and (II) corresponds to the sample after pre-Irr $(240\times {10}^{-6}$ dpa), low-T Irr $(100\times {10}^{-6}$ dpa), and annealing at 400 K.