Theory of theα−γPhase Transition in Metallic Cerium

Abstract

A simple model for the $\alpha -\gamma$ phase transition in Ce is presented. It is based on the change of occupation number of the $f$ levels, which are assumed to be atomiclike in character, i.e., highly correlated and with a very narrow bandwidth. The change in occupation number is, as a function of temperature, caused by the short-range part of the electron-electron interaction. The theory allows for the existence of a critical point. With the assumption of a linear relationship between $f$-level occupation numbers and lattice constant, pressure-latticeconstant isotherms are calculated. Curves for the paramagnetic susceptibility as a function of pressure and temperature are also presented.