Local Spin Density Functional Calculations Research Articles

Electronic and magnetic structure of BCC Fe-Co alloys from band theory

The connection between electronic structure and ferromagnetism is studied for the Fe-Co alloy system by means of self-consistent local spin-density functional calculations. The local environment of these BCC-substitutional alloys is modelled by different ordered compounds: besides BCC Co and Fe these are Co3Fe and Fe3Co in the Fe3Al structure and FeCo in the CsCl and NaTl structures. FeCo in the CsCl structure is studied in great detail giving the ferromagnetic band structure, decomposed state densities, Wigner delay times and the spatial form of the spin density. The role of the nearest-neighbour coordination in determining the value of the magnetic moments is discussed for all the compounds studied. The calculated and measured magnetic moments are compared and trends are analysed and explained.

Electronic structure calculations and magnetic properties

Recent theoretical developments in the study of the electronic structure and magnetic properties of itinerant magnets are reviewed. The discussion falls naturally into two parts. The first part deals with the apparent success of the local spin density functional calculations in predicting ground state properties such as the magnetic moment or equilibrium atomic volume with the help of no adjustable parameters. The second part deals with the conditions for the existence of localized moments in the disordered paramagnetic phase and examines the energetics of different local moment configurations within a parametrized tight-binding framework. The relevance of these results to current theories of itinerant magnetism is stressed.