111Cd(←111In) time differential perturbed angular correlation (TDPAC) spectroscopy in Fe/Ag films

We have investigated the magnetic properties of Cd atoms decayed from In-111 at the interfaces of Fe/Ag evaporated films. In order to determine the magnetic properties of the films, we have measured Cd-111(<- 111 In) 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 In-111 were evaporated by resistance-heating. The evaporated films had the following stacking orders on kapton polyimide film substrate: (1) polyimide/Fe 50 nm/In-111/Fe x nm/Ag 20 nm (x = 0.2, 0.3, 1, 3, 5, 10), (2) polyimide/Fe 50 nm/Ag x nm/In-111/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 In-111 is close to the interface of the Fe/Ag layer. The intensity of perturbation damps rapidly as In-111 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.