Two series of Fe/Ag multilayers were grown in a Perkin-Elmer 430B MBE system, one of the Fe(110)/Ag(lll) orientation and another of the Fe(100)/Ag(100) orientation. Vastly different techniques were developed by this group and others to achieve epitaxial growth of both of these systems. Using RHEED, it was inferred that the optimal growth of Fe(110) on Ag(lll) occurred at a substrate temperature of 180° C. In contrast, the growth of Fe(lO0)/Ag(100) proceeded with the sharpest RHEED streaks at a reduced substrate temperature. We believe that these fundamentally different growth parameters are the result of physically different growth modes, conjectured to be: edge growth (Fe 110), and a more nucleated growth (Fe 100).
Accordingly, dissimilar magnetic interfacial properties are also strongly in evidence, accounted for by the structural differences associated with the different Fe planes. Furthermore, Fe(110) layers as thin as 3 ML were grown on Ag(lll) and showed no superparamagnetism and a genuine 2-dimensional behavior of M(T). However, the Fe(100) on Ag(100) multilayers in a similar thickness range exhibited strong relaxation and a comparatively reduced Curie temperature.