Calculation of spin and orbital magnetizations in Fe slab systems at finite temperature

Abstract

The temperature dependence of spin and orbital local magnetizations is theoreticallydetermined for the non-bulk atomic region of (001) and (110) Fe slab systems. A dband Hamiltonian, including spin–orbit coupling terms, was used to model theslabs, which were emulated by using Fe films of sufficient thickness to reach abulk behavior at their most inner atomic layers. The temperature effects wereconsidered within the static approximation and a simple mean field theory wasused to integrate the local magnetic moment and charge thermal fluctuations.The results reflect a clear interplay between electronic itinerancy and the localatomic environment and they can be physically interpreted from the local smallcharge transfers occurring in the superficial region of the slabs. For recovering theexperimental behavior on the results for the (001) slab system, the geometricalrelaxations at its non-bulk atomic layers and a d band filling variation are required. Astudy on the magnetic anisotropy aspects in the superficial region of the slabs isadditionally performed by analyzing the results for the orbital local magnetizationcalculated along two different magnetization directions in both slab systems.