Lattice parameters of Bi-Sb alloys at 4.2°K

Lattice parameters of Bi-Sb alloys up to 12.5 at. % Sb have been measured at the liquid He temperature. The results indicate a linear dependence on composition of the hexagonal a axis and a slightly curved behaviour of the c axis in this concentration range. There is a pronounced deviation from a Vegard-type interpolation for the c axis reflected also in the c/a ratio. The bonding scheme in these alloys is discussed briefly with reference to the dependence of the structural parameters on the Sb concentration.