Investigation of short-range order by electrical resistivity measurement

Abstract

The paper gives an overview over recent results on short-range order effects in three binary alloy systems, CuZn, AgAl and CuMn, obtained by measuring changes in the residual electrical resistivity. It turns out that this method because of its great experimental simplicity in combination with a high measuring accuracy is particularly suited to gain information on equilibrium and kinetics of SRO. It gives a reflection of the interaction energies between the allow atoms yielding the dependence of SRO on temperature and concentration, the ordering energies, the kinetics of SRO-relaxation (single exponential or not), SRO-relaxation times and the sign and value of SRO-induced electrical resistivity. One of the main advantages of the method is the information about the influence of the thermal treatment and pre-treatment on the thermodynamical state of the sample, which may be of great use for the application of other measuring methods. A comparison of experimental results with model calculations was already successful for SRO equilibrium values. It allows a direct calculation of SRO-parameters from the results of resistivity measurement, which are in good correspondence with results of diffuse scattering experiments. More difficulties arise for an explanation of not single-exponential SRO kinetics. Further it is shown that interesting diffusion parameters like the activation energy of formation and migration of vacancies as well as the activation energy of self-diffusion can be measured at very low defect concentrations.