Thermochemistry of the gadolinium-copper interface

Authors

D. LaGraffe, Syracuse University
Peter A. Dowben, University of Nebraska-LincolnFollow
M. Onellion, University of Wisconsin-Madison

Date of this Version

August 1989

Comments

Published by American Physical Society. Copyright 1989. Permission to use. Phys. Rev. B40 (1989) 3348-3351. http://prb.aps.org/.

Abstract

We have characterized the thermochemistry of the gadolinium-copper interface using valence-band photoemission. We find that the copper substrate binds strongly with the gadolinium overlayer, based upon valence-band binding-energy shifts that occur with increasing gadolinium coverages on Cu(100). The net potential for copper at the interface is 3.82 eV/atom which is some 0.51 eV/atom greater than the heat of sublimation for copper. The strong bonds formed between copper and gadolinium provide a thermochemical driving force for copper gadolinium-alloy formation. We observed a surface-to-bulk core-level shift for gadolinium of 0.3–0.4 eV. We also observed a Cu 3d binding-energy increase of 0.73 eV with increasing coverage.