PHYSICAL REVIEW LETTERS, vol.93, no.18, 2004 (SCI-Expanded)
de Haas-van Alphen measurements on CexLa1-xMIn5 yield contrasting types of behavior that depend on whether M = Co and Ir or M = Rh. A stronger x-dependent scattering in the case of M = Co and Ir is suggestive of a stronger relative coupling, J/W, of the conduction electrons to the 4f electrons, which would then account for the development of a heavy composite Fermi-liquid state as x --> 1. The failure of a composite Fermi-liquid state to form for any x in the case of M = Rh is shown to be inconsistent with theoretical models that propose antiferromagnetism to result from spin-density-wave formation.