Regensburg 2000 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

AM: Magnetismus

AM 4: Magnetokristalline Anisotropie, Magnetostriktion

AM 4.4: Vortrag

Montag, 27. März 2000, 12:15–12:30, H22

Magnetocrystalline anisotropy in ferromagnetic-semiconductor multilayers — •I. Cabria¹, A. Perlov², and H. Ebert¹ — ¹Institut für Physikalische Chemie, Universität München, Butenandtstr. 5-13, 81377 München — ²Institute of Metal Physics, Academy of Sciences of Ukraine, Kiev

We have calculated the magnetocrystalline anisotropy energy (MAE) for ferromagnetic-semiconductor multilayers (bcc-Fe with GaAs and bcc-Fe with Ge) using the spin-polarized relativistic LMTO method and simulating the multilayers as superlattices. We have calculated the spin-orbit induced electronic MAE by means of the so-called force theorem and included the contribution from the dipolar-dipolar interaction. In particular, the dependence of the electronic MAE with the number of bcc-Fe layers (between 1 and 9 Fe layers and 5 Ge or GaAs layers) has been studied. The electronic MAE is negative (this favours perpendicular orientation of the magnetic moment) and in general decreases when increasing the numbers of Fe layers, with some oscillations. The dipolar MAE, on the other hand, is positive (on-plane magnetic moment) and increases with the number of Fe layers, but it does not overcome the electronic MAE. Hence, the total MAE is negative and in general decreases with the number of Fe layers. We have decomposed the electronic MAE layer by layer and found that the electronic MAE of the Fe layer at the interface is negative in almost all the multilayers and it is primarily responsible for the electronic MAE. The MAE of the others Fe layers is positive and the MAE of the Ga, As and Ge is small and negative.