Hyperfine fields and spin orientations in (Fe57/Ag) superlattices from conversion electron Mössbauer studies (invited)

Abstract

Conversion electron Mössbauer studies have been carried out as a function of temperature on a series of single‐crystal [(100)⁵⁷Fe/(100)Ag] superlattices grown by MBE on GaAs substrates. The ⁵⁷Fe layer thickness was varied from approximately 1 to 5.5 ML. From the relative intensity of the Mössbauer lines we show conclusively that the orientation of the magnetic moment for films 2.4 ML and thinner in zero applied field is perpendicular to the film plane at low temperatures. For a 5.5‐ML film the spin alignment at room temperature is in the film plane and partially out of the plane at low temperatures. The low‐temperature magnetic hyperfine fields are enhanced relative to bulk Fe.