Magnetic short range order above the Curie temperature in Fe and Ni

Abstract

We report the first results of time-dependent density functional simulations of magnetic properties of Fe and Ni at finite temperatures. They reveal the existence of local moments in Ni above the Curie temperature, coupled to strong short range order. In Fe the short range order is also present to a lesser extent but spin wave like excitations persist in both materials well above the Curie temperature in the paramagnetic state. The prevailing view of magnetic order should be reconsidered in light of these findings.