AVS 45th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Thursday Sessions
       Session MI-ThA

Paper MI-ThA7
Fermi Surface Study of Pseudomorphic Fe@sub 1-x@Ni@sub x@ and Co@sub 1-x@Ni@sub x@ Thin Films on Cu(100)

Thursday, November 5, 1998, 4:00 pm, Room 324/325

Session: Structure & Magnetism of Surfaces & Interfaces
Presenter: M. Hochstrasser, Pennsylvania State University
Authors: M. Hochstrasser, Pennsylvania State University
F.O. Schumann*, Pennsylvania State University
R.F. Willis, Pennsylvania State University
T.R. Cummins, University of Missouri, Rolla
G.D. Waddill, University of Missouri, Rolla
S.R. Mishra, Lawrence Livermore National Laboratory
J.G. Tobin, Lawrence Livermore National Laboratory
E. Rotenberg, Lawrence Berkeley National Laboratory
Correspondent: Click to Email
We report angle resolved photoemission studies of the electronic behavior of ultrathin epitaxial layers of fcc structured binary alloys, Fe@sub 1-x@Ni@sub x@ and Co@sub 1-x@Ni@sub x@, deposited by molecular beam epitaxy on Cu(100) substrates. In particular, we have used Fermi surface mapping to monitor changes in the Fermi surface with increasing magnetization density. Fermi surface mapping has shown to be a valuable method to investigate for example the collapse of the exchange splitting between the upper and lower d-band in Ni@footnote 1@ and surface electronic states of hydrogen adsorbed on W(110).@footnote 2@ Co@sub 1-x@Ni@sub x@ and Fe@sub 1-x@Ni@sub x@ binary alloys show a different behavior in the bulk. Co@sub 1-x@Ni@sub x@ is structurally and magnetically well-behaved. In particular the magnetic moment varies linearly as a function of concentration. This is in sharp contrast to fcc Fe@sub 1-x@Ni@sub x@ which displays a magnetic instability at ~65% Fe content. An extended regime of fcc stability is possible via epitaxy on Cu(100).@footnote 3@ We investigated the changes in the Fermi surfaces of Fe@sub 1-x@Ni@sub x@ and Co@sub 1-x@Ni@sub x@ pseudo-morphic film alloys depending on various concentrations of Ni in a large photon energy regime and compared these measurements with the known Fermi surface of Ni(100), Cu(100) and Co(100). We observe a change in the Fermi surface with increasing magnetization density e.g. number of holes in the d-band by changing the stoichiometry of our samples. @FootnoteText@ *present address: Department of Chemistry and Material Science, Lawrence Livermore National Laboratory, U.S. @footnote 1@T. Greber et al., Phys. Rev. Lett. 79, 4465 (1997). @footnote 2@E. Rotenberg et al., Phys. Rev. Lett. 80, 2905(1998). @footnote 3@F.O. Schumann et al., Phys. Rev. Lett. 79, 5166 (1997).