Magnetic studies of Fe-Y compositionally modulated thin films

Abstract

Compositionally modulated thin films of Y/Fe have been studied by using SQUID magnetometry. Samples were grown by electron‐beam evaporation onto Kapton substrates. In the low applied field regime, the samples show irreversible behavior when they are submitted to ZFC‐FC magnetization processes, increasing the irreversibility zone as the thickness of the Fe layers increases. In the high applied magnetic field regime (H≥10 000 Oe), samples show ferromagnetic behavior. The temperature dependence of the saturation magnetization has been studied, and it was found that both spin‐wave excitations and Stoner excitations occur at temperatures higher than 40 K, and a marked deviation from the T3/2 law was noted below 30 K.