Influence on the physical behavior of boron substitution in Ce5Si3

The binary compound Ce5Si3 has been investigated with respect to the possibility to substitute boron in its matrix and the influence on the physical properties. The small amount of substituted boron (∼1 at%) hardly changes the lattice parameters of the tetragonal Cr5B3 type of structure. The observed antiferromagnetic transition at TN=6 K for the pure binary compound, however, is suppressed or shifted to well below 4 K. The enhanced metallic character of the borosilicide seems to be induced by electron transfer from the boron into the conduction band. Observed peaks at T∼20 K and a negative logarithmic temperature dependence of the spin disorder resistivity stems from the combined influence of the Kondo effect and crystal-field interactions. The lanthanum-silicide La5Si3 is a Pauli-type temperature independent paramagnet down to 4 K. The ρ(T) plot reflects the metallic character of a nonmagnetic compound