The lattice spacings of close-packed hexagonal Au-In, Au-Cd, and Au-Hg alloys

Abstract

The lattice spacings of close-packed hexagonal gold-rich phases in the systems Au-In, Au-Cd, and Au-Hg have been determined as a function of composition and electron: atom ratio, using quenched alloys, X-ray powder methods, and Geiger counter diffractometry. The results show that an increase in the number of electrons per atom does not affect the axial ratio in Au-Hg alloys, and leads to a slight decrease of axial ratio in Au-Cd alloys and a considerable decrease with a change of slope in Au-In alloys. The changes in Au-In alloys have been verified at temperatures of liquid nitrogen and liquid helium. These phenomena may be interpreted in terms of interactions of the Fermi sphere with the appropriate Brillouin Zone faces both before contact with them and after overlaps.