STRUCTURE AND INTERMIXING IN FE FE(110) AND FE/AG/FE(110) MULTILAYERS/

We have previously shown, in UHV-SEM studies of Ag/Fe(110), that Ag(ll l) islands grow on top of two intermediate monolayers of AE in the Str anski-Krastanov (SK) mode, In the present work, Fe was deposited on sa mples consisting of (1-5 ML) annealed Ag layers on Fe(110). Growth, st ructure and intermixing were monitored by biased secondary electron im aging (b-SEI), reflection electron diffraction (RHEED) and Auer electr on spectroscopy (AES). Ar room temperature (RT), Fe islands grow in a (110) orientation on (1-2 ML) Ag(111)/Fe(110). Due to kinetic limitati ons, these islands form facets similar to those obtained in the Fe/Fe( 110) system. These limitations are overcome in the Fe/Fe(110) system b y depositing at 250 degrees C. All three orientations in the Nishiyama -Wassermann relationship are observed for Fe islands grown on thicker, bit not on thinner. Ag layers. Quantitative AES indicates that there is intermixing at the monolayer level between the deposited Fr atoms a nd underlying Ag layers even at RT, During annealing, or for depositio n at 250 degrees C, Ag atoms undergo long range diffusion towards the top of the deposit, but kinetic limitations are not completely overcom e for 5 ML Ag layers: for thinner layers, the Fe islands flatten Formi ng additional substrate layers at the Ag/Fe(110) interface, (C) 1998 E lsevier Science B.V. All rights reserved.