Temperature dependent magnetic properties of thin films and bulk ferromagnets: an implementation of the disordered local moment scheme

Abstract

In the present work an implementation of the relativistic disordered local moment scheme (DLM) within the Screened Korringa-Kohn-Rostoker (KKR) Green's function formalism is presented. This approach is applicable to describe the magnetic properties of ferromagnetic metals and alloy systems at finite temperature.<br />The screened KKR facilitates to treat half infinite systems, such as thin films.<br />As an application we present a method to calculate the temperature dependent magnetic anisotropy of magnetic thin films, and show an application to Co$_n$Cu(100) thin film structures. We interpret our ab initio results with the help of an anisotropic classical Heisenberg model.<br />To highlight the importance of a non-unitary Heisenberg exchange we investigate also the magnetic ordering of a Mn monolayer on W surface, and stress the relevance of the so-called Dzyaloshinskii-Moriya interactions.<br />In the third part of the thesis we apply the DLM formalism to calculate the magnetic part of the electric resistivities.<br />We implement the DLM using the Kubo-Greenwood equation within the KKR framework.<br />This work represents the very first ab initio approach in the literature of this field.<br />As an application we show the results for bulk Fe and Co.