Photoemission and electronic structure of tungsten-based metallic glasses and alloys

Authors

• M.A. Engelhardt, University of Nebraska - Lincoln
• Sitaram Jaswal, University of NebraskaFollow
• David J. Sellmyer, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

December 1991

Comments

Published by American Physical Society. Phys. Rev. B 44, 12671 (1991). http://prb.aps.org. Copyright © 1991 American Physical Society. Permission to use.

Abstract

The structure and electronic density of states of intertransition-metal glasses of the form T_xW_1-x have been investigated, where T=Cu, Ni, and Co. The film samples were prepared by cosputtering in a chamber with a rapidly rotating, water-cooled substrate. Experiments included x-ray diffraction and ultraviolet photoemission at photon energies of 21.2 and 40.8 eV, and electronic-structure calculations were performed with a self-consistent linear combination of muffin-tin-orbitals method. For the calculations the structures were simulated by either disordered crystalline or amorphous clusters of 60–64 atoms in a periodically extended supercell. The range of amorphous alloy formation was determined approximately for each alloy series, and it was found that this range was larger when the atomic-radii difference of the two elements is larger. In both the photoemission and theoretical results for the crystalline and amorphous Cu-W alloys the Cu 3d band is a distinct feature whose position is well reproduced by the calculations. In the Ni-W and Co-W alloys the 3d and 5d bands overlap significantly. In the case of crystalline Ni-W alloys, the theory gives a good representation of the observed occupied density of states.