EVOLUTION OF THE SPIN-ORBIT EXCITATION WITH INCREASING KONDO ENERGY IN CEIN3-XSNX

Neutron scattering measurements on CeIn3 show the F-2(5/2) --> F-2(7/2) spin-orbit excitation at approximately 273 meV of half-width GAMMA approximately 18 meV, while CeSn3 reveals a broad excitation (GAMMA approximately 70 meV) at a significantly higher energy (approximately 345 meV). With increasing Sn content x, hence increasing Kondo energy, the series of compounds CeIn3-xSnx show a progressive upward energy shift of the excitation. This is accompanied initially by a collapse of the crystal-field splitting and beyond x approximately 1 by a concomitant increase in width.