Magnetic ordering and non-Fermi liquid scaling in Kondo lattice systems

Muon spin relaxation (μ+SR) investigations of CeCoGe1.8Si1.2, which is close to a quantum critical concentration as suggested by Eom et al. [2], show magnetic ordering with a transition temperature of ∼0.5 K for the first time. The zero-field relaxation rate λf follows a power law of temperatures between 0.7 and 1 K, where the specific heat divided by temperature (C/T) scales with logT, and possibly demonstrate non-Fermi liquid (NFL) scaling. We suggest that magnetic disorder which introduces inhomogeneities in the Kondo temperatures and RKKY exchange coupling strengths of Ce ions as a possible origin of NFL behaviour. (author)