High pressure and field response of YbCu4AuxAg1− x

YbCu 4 Au x Ag 1− x provides the possibility to study a crossover from high to low T K systems and therefore from coherent to incoherent behaviour. Although this series is isoelectronic, details in the electronic structure appear to be the driving force for different ground state properties, rather than chemical pressure due to the Au/Ag substitution.