Thickness‐dependent interface magnetism of Fe/Cr/Fe trilayers

Abstract

Electronic structure and magnetic properties of Fe N /Cr 3 /Fe N bcc (100) trilayers (N is the number of atomic layers) are studied on the basis of ab initio calculations performed within the framework of the density functional theory in the local spin density approximation, using the full-potential LAPW method in slab geometry. According to our calculations, the magnetic moment of a surface Fe layer increases monotonically from 2.45 B for N ϭ 1 to 2.92 B for N ϭ 3 and practically does not change at further increase of the Fe film thickness. However, the magnetic moment in the interface Fe layer changes nonmonotonically with the Fe film thickness increase and is close to the surface value at N ϭ 5 and 7.

Ab initio calculations of magnetic properties of Fe–Cr trilayer as a function of ferromagnetic slab thickness

“…A complete discussion of this behavior can be found in Ref. 9. That reference states that the large magnetic moment is mainly due to resonances with a high degree of localization in the interface layer introduced by quantum‐well states.…”

Influence of interfacial scattering and surface roughness on giant magnetoresistance in Fe/Cr trilayers using ab initio layer potentials

“…The sum over the spin contribution allow us to define the P a and P b parameters: P as þ P aÀs ¼ P a and P bs þ P bÀs ¼ P b : In semiclassical approach, the interfaces A and B of trilayer are represented by the parameters S As ; S AÀs ; S Bs and S BÀs which can vary from 0 to 1 and they are the factors that indicate the degree of electron scattering at interfaces A and B for spin s and Às: It was reported in Ref. [10] that a large magnetic moment appears in the interface layer, mainly due to highly localized interface states. It means that for a certain configuration of the Fe/Cr interface, the peak of the potential appears and it constitutes the physical source of scattering for an electron with a given spin.…”

Calculations of giant magnetoresistance in Fe/Cr trilayers using layer potentials determined fromab initiomethods

“…However, the localization of these states near the interface means that they should not be affected by the thickness of the Fe film and the magnetic moments near the Fe/Cr interface should be independent of Fe film thickness. This is a feature that, in our opinion, is due to the QW states, which are delocalized throughout the slab and their energy changes together with increase of the Fe film thickness [29]. The QW states have a resonance with the interface states for n = 4, 6, 8.…”