Fermi energy and Fermi surface distortion of the Cs-K, Cs-Rb and Rb-K binary systems

Systematic theoretical investigation of the Fermi energy (FE) and the Fermi surface distortion (FSD) of Cs0.7Rb0.3, Cs0.3Rb0.7. CS0.7K0.3 Cs0.3K0.7, Rb0.71K0.29 and Rb0.3K0.7 disordered alloys have been reported for the first time by using the pseudo-alloy-atom model. A local pseudopotential consisting of a Coulombic term outside the core and varying cancellation of interaction within the core is proposed to describe the electron-ion interaction in each of these systems. The influence of various local-field correction functions on the aforesaid properties is 64-93%. The distortion of the Fermi surface (FS) along major symmetry directions obeys the metallic behavior. For the Cs1-xRbx and Cst-xKx systems, the FSD along the zone boundaries increases with the atomic volume. For Rb1-xKx, a reverse trend is observed. The maximum anisotropy in the FS for the six binaries is observed at the [1 1 0] point. (C) 2001 Elsevier Science B.V. All rights reserved.