Crystal-field splitting and magnetic relaxation inCeCu20.2Si2

We present the results of two types of inelastic neutron scattering experiments on the heavy-fermion system ${\mathrm{CeCu}}_{2\pm 0.2}$ ${\mathrm{Si}}_2$ 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 γ-cerium and α-cerium. The scattering intensities are compared with static susceptibility measurements.