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Measurements of the tracer diffusion of Au in amorphous, melt-spun Pd78Cu&16 have been carried out during low-flux ion irradiation. The changes in the depth profiles of implanted Au due to diffusion were determined by Rutherford-backscattering spectrometry. Ion mixing is negligible due to the small integrated irradiation doses used in the experiments. The irradiation enhances the diffusion. With more than an order of magnitude, the enhancement saturates at higher doses. The temperature dependence of the diffusion is similar with and without irradiation. The results are discussed in the context of the migration of vacancylike defects produced during irradiation, like radiation-enhanced diffusion observed in crystalline materials. Introduction.* * * K. SAMWER (Gottingen) is gratefully acknowledged for supplying the melt-spun samples. Our thanks are due to J. CHEVALLIER for his patience and skill with the TEM studies, to J.

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Diffusion during He, Ne+, and Xe+ irradiations of trace amounts of Au in melt-spun amorphous Pd78Cu6Si, 6 has been experimentally investigated. Diffusion constants were measured by following the changes in ion-implanted Au profiles with Rutherford-backscattering spectrometry.Heat treatments and simultaneous irradiations were performed as a function of temperature (533-588 K), ion flux, and ion mass. Total integrated fluences being very small, ion-beam-mixing effects are negligible. More than an order of magnitude enhancement in the diffusion was observed because of irradiations. This enhancement saturates at higher fluxes, the level being independent of ion mass, i.e. , independent of collision-cascade parameters. Except at higher temperatures, where the enhancement decreases, the temperature dependence of the diffusion-saturation level is similar to that of the diffusion without irradiation. The data suggest that vacancylike defects play a significant role in the diffusion.

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