INFRARED-ABSORPTION OF FE ULTRATHIN FILMS ON IONIC-CRYSTALS

Ultrathin (<100 Angstrom) metal films as well as island metal films co uld be considered as systems of reduced dimensionality. The motion of free carriers is confined by film and island boundaries, which affects , for example, the infrared absorption. We have studied the infrared t ransmission (from 900 to 4100 cm(-1)) of ultrathin metal films grown i n situ on ionic crystal surfaces. Obviously, both the reduced dimensio nality and the film morphology strongly influence the infrared spectra . Experimental spectra of ultrathin Fe films (thickness <30 Angstrom o n KBr(100) could not be described in terms of Fe-bulk parameters. (C) 1998 Elsevier Science B.V. All rights reserved.