Magnetically Active Lanthanide Silicide Blocks with a Strong Spin–Orbit Coupling for the Design of Magnetic Heterostructures

The rapid development of the element base for devices in the nanometer range requires magnetically active nanostructures for integration into multilayer architectures, which is particularly important for spintronics. Four-layer Si–T–Si–Ln systems (T is a transition metal and Ln is a lanthanide) of strongly correlated LnT 2 Si 2 intermetallics with a tetragonal ThCr 2 Si 2 structure have been proposed in this work as elementary blocks of such architectures. The combined results of photoemission studies and ab initio calculations of the band structure of the GdIr 2 Si 2 and TbIr 2 Si 2 antiferromagnets are presented. The calculations are in agreement with the experiment. Model heterostructures composed of four-layer structural blocks of these antiferromagnets, where Ln atoms in a magnetic sublattice alternate every one or two layers have been theoretically studied. Detailed information on the magnetic properties of such superlattices, including magnetic anisotropy and the orientation of 4 f moments has been obtained. It has been found that the moments of the Gd atoms are oriented in the direction of the moments of the Tb atoms, and their parallel or antiparallel alignment is determined by the specific order of alternation of the atoms in the magnetic sublattices, which leads to either the emergence or the cancellation of the total magnetization along the crystallographic c axis. The results obtained and the proposed approach open new possibilities for designing nanostructured materials composed of such structural blocks with flexibly controllable magnetic characteristics.