Oscillatory spin polarization and magneto-optical Kerr effect in Fe₃O₄ thin films on GaAs(001)

Yan Li; Wei Han; A G Swartz; K Pi; J J I Wong; S Mack; D D Awschalom; R K Kawakami

doi:10.1103/PhysRevLett.105.167203

Oscillatory spin polarization and magneto-optical Kerr effect in Fe₃O₄ thin films on GaAs(001)

Phys Rev Lett. 2010 Oct 15;105(16):167203. doi: 10.1103/PhysRevLett.105.167203. Epub 2010 Oct 12.

Authors

Yan Li¹, Wei Han, A G Swartz, K Pi, J J I Wong, S Mack, D D Awschalom, R K Kawakami

Affiliation

¹ Department of Physics and Astronomy, University of California, Riverside, California 92521, USA.

PMID: 21231004
DOI: 10.1103/PhysRevLett.105.167203

Abstract

The spin dependent properties of epitaxial Fe₃O₄ thin films on GaAs(001) are studied by the ferromagnetic proximity polarization (FPP) effect and magneto-optical Kerr effect (MOKE). Both FPP and MOKE show oscillations with respect to Fe₃O₄ film thickness, and the oscillations are large enough to induce repeated sign reversals. We attribute the oscillatory behavior to spin-polarized quantum well states forming in the Fe₃O₄ film. Quantum confinement of the t(2g) states near the Fermi level provides an explanation for the similar thickness dependences of the FPP and MOKE oscillations.