Modeling interlayer exchange coupling in EuS/PbS/EuS trilayers

All-semiconducting EuS/PbS/EuS trilayers that show antiferromagnetic coupling were studied by superconducting quantum interference device magnetometry. We analyzed our measurements with a modified Stoner-Wohlfarth model from which the interlayer exchange energy and anisotropy were extracted based on the switching field from antiparallel to parallel alignment of the EuS layers and the zero-field susceptibility, respectively. Magnetic moment versus temperature curves were simulated by taking into account Brillouin type temperature dependence of the saturation magnetization of EuS. Despite their simplicity, the simulated curves show good qualitative agreement with the measurements when strong temperature dependence of interlayer coupling is assumed. (C) 2004 American Institute of Physics.