Relaxation of magnetic properties of [Pt/Co]/IrMn multilayer films during annealing and natural aging

The purpose of the work is to study multilayer Pt/[Pt/Co]$_5$/IrMn films, in which the cobalt thickness varies from 0.6 to 1.5 nm, namely, to study changes in their magnetic properties that occur under the influence of thermal annealing and during natural aging. The samples were prepared by high-vacuum magnetron sputtering; their structure and properties were studied by magneto-optical Kerr magnetometry and transmission electron microscopy. It was found that natural aging only leads to a decrease in the exchange shift, while during thermal annealing in a zero magnetic field, a decrease in the exchange shift is accompanied by an increase in coercivity. These effects are more pronounced in structures with thin films of cobalt, with a thickness of less than 1 nm.