It has been proposed that Permalloy (Ni0.8Fe0.2) can be used as thin-film magnetic bubble generator and sensor, and Au is a proposed electrical connector for input/output. We find that significant interdiffusion occurs to levels of 1-10 at.% for the diffusion couples Ni/Au, Fe/Au, and Permalloy/Au. We have determined 350°C solubility levels for all pairs for 1100-Å films for annealing times from 10 to 2400 min. There was no degradation of electrical or magnetic properties of the Permalloy/Au system even at the highest levels of interdiffusion, indicating that it is ideally suited for a magnetic bubble metallurgy. © 1974 American Institute of Physics.