Crystal field studies on the heavy fermion compound CeNi${}_8$CuGe${}_4$

Abstract

Substitution of nickel by copper in the heavy fermion system CeNi${}_{9-x}$Cu${}_x$Ge${}_4$ alters the local crystal field environment of the Ce${}^{3+}$-ions. This leads to a quantum phase transition near $x\approx 0.4$, which is not only driven by the competition between Kondo effect and RKKY interaction, but also by a reduction of an effectively fourfold to a twofold degenerate crystal field ground state. To study the consequences of a changing crystal field in CeNi${}_8$CuGe${}_4$ on its Kondo properties, inelastic neutron scattering (INS) experiments were performed. Two well-defined crystal field transitions were observed in the energy-loss spectra at 4 K. The crystal field level scheme determined by neutron spectroscopy is compared with results from specific heat measurements.

4 pages, 3 figures, conference SCES09

References in corpus (1)

• Evolution of Quantum Criticality in CeNi_{9-x}Cu_xGe_4