Crystal-field splitting and magnetic relaxation in CeCu20.2Si2.

Abstract

We present the results of two types of inelastic neutron scattering experiments on the heavy-fermion system ${\mathrm{CeCu}}_{2\ifmmode\pm\else\textpm\fi{}0.2}$${\mathrm{Si}}_{2}$ to investigate the quasielastic scattering (low-energy response) and the crystal-field (CF) excitations (high-energy response). A characteristic energy width of about 0.7 meV is found for the magnetic low-energy response at low temperatures, and the CF scheme given earlier for ${\mathrm{CeCu}}_{2}$${\mathrm{Si}}_{2}$ is roughly confirmed. The inelastic spectrum of ${\mathrm{CeCu}}_{2.2}$${\mathrm{Si}}_{2}$ gives some indications for a coexistence of \ensuremath{\gamma}-cerium and \ensuremath{\alpha}-cerium. The scattering intensities are compared with static susceptibility measurements.