The lattice constant and itinerant electron metamagnetic transition in Laves-phase pseudo-binary Lu(Co_1-xSi_x)₂ compounds

The lattice constant, low-temperature specific heat and high-field magnetization of the Laves-phase itinerant electron metamagnets Lu(Co_1-xSi_x)₂ have been investigated. By partial substitution of Co by Si, the critical field H_c of the metamagnetic transition decreases and the temperature T_max of the magnetization maximum shifts to lower temperatures with increasing x regardless of the decrease in the lattice constant. Both the electronic specific heat coefficient gamma and the magnetic susceptibility chi increase with increasing x up to x=0.09 and decrease above this concentration. The present results suggest that the decrease in the critical field is not due to the increase in the lattice constant but is due to the hybridization between 3d electrons of Co and 3p electrons of Si.