Substrate-induced magnetic ordering of rare-earth overlayers

Authors

Peter A. Dowben, University of Nebraska-LincolnFollow
D. LaGraffe, Syracuse University
Dongqi Li, yracuse University, Syracuse, New York
A. Miller, Syracuse University
Ling Zhang, Syracuse University
L. Dottl, University of Wisconsin-Madison
M. Onellion, University of Wisconsin-Madison

Date of this Version

February 1991

Comments

Published by American Physical Society. Copyright 1991. Permission to use. Physical Review B 43 (1991) 3171–3179. http://prb.aps.org/.

Abstract

We have studied the magnetic ordering of terbium overlayers on Cu(100) and Ni(111), using angle-resolved photoemission. The 5p_3/2 to 5p_1/2 shallow-core-level branching ratios in different photoemission geometries provide a measure of the magnetic ordering in rare-earth-metal overlayers as a result of final-state effects in photoemission. We find that ferromagnetic substrates order paramagnetic terbium overlayers. This induced magnetic ordering is not a crystal-field effect and can be modeled by Ginzburg-Landau theory. Application of Ginzburg-Landau theory to our results suggests that the correlation length of paramagnetic terbium κ^-1 is between 2.5 and 3.5 Å. Reversible increases in the extent of magnetic ordering at temperatures below the Tb Curie temperature are observed for terbium overlayers on both Cu(100) and Ni(111).