Element-Specified Observation of Surface-Influenced Magnetization Process in Gd/Fe Multilayer

Abstract

Element-specific magnetic field hysteresis on a Fe(20 Å)/[Gd(30 Å)/Fe(20 Å)] × 50 multilayer has been measured by means of X-ray magnetic circular dichroism at Gd-L₃ and Fe-K edges at 16 K, 195 K and 300 K, together with bulk magnetization measurements. These results are examined on the basis of Camley’s model, which describes the multilayer as a one-dimensional spin chain. At 195 K, which is near the compensation temperature, the observed hysteresis curve is interpreted as a series of magnetic states: canted Fe-aligned, surface-twisted, and Fe-dominant bulk-twisted states. These unique spin configurations are promoted by the surface magnetization of outermost Fe slabs and the exchange-spring-like behavior within Gd slabs.