Surface characterization of Al-Cu-Fe thin films by scanning tunneling microscopy and scanning tunneling spectroscopy

Thin films of disordered Al63Cu25Fe12 alloy have been prepared by thermal e vaporation and characterized using d.c. electrical resistivity and scanning tunneling microscopic (STM) and spectroscopic (STS) measurements. The loca l microscopic and spectroscopic data suggest that the samples comprise of a t least two different regions, one with a metal like density of states whil e the other having a clear gap like feature at the Fermi level in the densi ty of states spectrum. The results may be attributed to the presence of che mical and topological disorders present in the sample. (C) 1999 Elsevier Sc ience B.V. All rights reserved.