VALENCE TRANSITION IN CHEMICALLY COLLAPSED CERIUM

The scaling behavior of the Landau equation of state which describes the valence transition in cerium is studied as a function of the size and valence of various chemical additives. Two major results are the relatively direct determination of the valence N of cerium at the critical point (viz., N=3.65) and the finding that the presence of chemical additives leads to a lattice-mediated rather than Coulombic bootstrapping term, which addresses the long-standing question of what is the driving mechanism for the valence transition. © 1979 The American Physical Society.