LOW-TEMPERATURE EFFECTS IN MAGNETIC SPECTRAL RESPONSE OF CEAL3-BASED SYSTEMS

Magnetic excitation spectra of Ce ions in CeAl3 and in the substituted systems Ce0.9Y0.1Al3 and Ce0.9Gd0.1Al3 were studied by inelastic neut ron scattering in the temperature range 0.03 K < T < 100 K. Below appr oximate to 60 K peak positions are strongly temperature dependent. The effect is enhanced due to chemical pressure and looks like a pure sin gle ion feature given by the interaction of the Ce ion with the conduc tion electrons. Additional investigations of the spectra of the parama gnetic impurity ion Pr3+ in CeAl3 and in the reference system LaAl3 sh owed an anomalous attenuation of the relaxation broadening for the CEF excitations in the CeAl3 matrix. All observed features are interprete d as a consequence of the Kondo ground state formation, strongly influ enced by the interaction between the crystalline electric field and th e local moment of the Ce Kondo ion.