NIST logo

Publication Citation: Non-collinear Exchange Coupling in Fe/Mn/Fe(001): Insight from Scanning Tunneling Microscopy

NIST Authors in Bold

Author(s): Daniel T. Pierce; Angela Davies; Joseph A. Stroscio; D Tulchinsky; John Unguris; Robert Celotta;
Title: Non-collinear Exchange Coupling in Fe/Mn/Fe(001): Insight from Scanning Tunneling Microscopy
Published: December 01, 2000
Abstract: The film growth and morphology of epitaxial Mn films grown on Fe(001) single crystal whiskers measured with scanning tunneling microscopy (STM) provides insight into the mechanism of interlayer exchange coupling in Fe/Mn/Fe(001) trilayers. The proximity model of Slonczewski for exchange coupling through an antiferromagnet predicts that the coupling angle between the ferromagnetic layers will oscillate around a mean value of 90° with an amplitude that is very sensitive to the width of the thickness distribution of the spacer layer. We measure the thickness distribution with the STM and find that the coupling angle variation predicted by the proximity model is qualitatively consistent with the actual coupling angle variations in Fe/Mn/Fe(001) measured with scanning electron microscopy with polarization analysis (SEMPA). Going beyond the proximity model and allowing for a non-uniform magnetization of the thin Fe overlayer provides an improved explanation of the results. We contrast the behavior of Fe/Mn/Fe(001), where the proximity model appears applicable, to coupling through antiferromagnetic Cr in Fe/Cr/Fe(001), where it is not, and discuss possible reasons for the difference.
Citation: Journal of Magnetism and Magnetic Materials
Volume: 222
Issue: No. 1-2
Pages: pp. 13 - 27
Keywords: antiferromagnetism;biquadratic coupling;interlayer magnetic coupling;non-collinear exchange coupling;scanning tunneling microscopy;thin film growth
Research Areas: Nanomagnetics
PDF version: PDF Document Click here to retrieve PDF version of paper (781KB)