111Cd((left arrow)111In) Time Differential Perturbed Angular Correlation (TDPAC) Spectroscopy in Fe/Ag Films

We have investigated the magnetic properties of Cd atoms decayed from 111In at the interfaces of Fe/Ag evaporated films. In order to determine the magnetic properties of the films, we have measured 111Cd((left arrow)111In) time differential perturbed angular correlation (TDPAC) spectra at room temperature as a function of distance from the interface. Fe and Ag were evaporated using electron beam evaporation, and small amounts of radioactive 111In were evaporated by resistanceheating. The evaporated films had the following stacking orders on kapton polyimide film substrate: (1) polyimide/Fe 50 nm/111In/Fe x nm/Ag 20 nm (x=0.2,0.3,1,3,5,10), (2) polyimide/Fe 50 nm/Ag x nm/111In/Ag 20 nm (x=0,0.2,1). We used an Ag layer as a cap layer in order to prevent oxidation in air. TDPAC spectra were measured using a four-detector arrangement. The hyperfine magnetic field tends to be slightly larger when 111In is close to the interface of the Fe/Ag layer. The intensity of perturbation damps rapidly as 111In is close to the interface of Fe and Ag. These behaviors are thought to depend on electric field gradients and the influence of the surface roughness.