EFFECTS OF INTERFACIAL ROUGHNESS ON SITE-PROBED MULTILAYERS OF FE(100) AG(100)/

Mossbauer spectroscopy was performed on three [Fe9(100)/Ag40(100)]25 m ultilayers grown by molecular beam epitaxy (MBE). All of the Fe bilaye r components in each sample were selectively loaded with 2 monolayers (ML) of Fe-57: at the Fe-on-Ag interfaces of one sample, at the Ag-on- Fe interfaces of another, and at the Fe bilayer centers of the third. The hyperfine fields, quadrupole splittings, and isomer shifts of thes e multilayers were measured at 16, 100 and 300 K. We observed widely d ifferent values and trends as the temperature increased, leading us to repeat an earlier claim that three rather than two distinct sites are needed to correctly describe the Fe bilayer components in Fe(100)/Ag( 100) multilayered systems.