ELECTRON-SPIN-RESONANCE INVESTIGATION OF THE HEAVY-FERMION COMPOUND CE(CU1-XNIX)(2)GE-2

The heavy-fermion compound Ce(Cu1-xNix)(2)Ge-2 is investigated by Gd3 electron spin resonance (ESR) within the whole concentration range (0 less than or equal to x less than or equal to 1). The Kondo-lattice s ystem exhibits an alloying-induced transition from an antiferromagneti cally ordered heavy-fermion ground state (x=0) to pure Kondo-like beha vior with strongly enhanced effective masses (x=1). The temperature de pendence of the ESR linewidth Delta H allows one to distinguish betwee n the different ground states. The nature of the magnetic order change s significantly from concentrations x less than or similar to 0.5 to x >0.5. The ESR data provide some further experimental evidence for a tr ansition from a local-moment type (x<0.5) to some kind of itinerant he avy-fermion band magnetism (0.5<x<0.8). Non-Fermi-liquid behavior is d iscussed for x=0.8 where the magnetism is suppressed. Our results agre e very well with the Cu-63 NMR spin-lattice relaxation rate 1/T-1 and the dynamic structure factor S(Q, omega) obtained from inelastic neutr on-scattering experiments.