Resistivity of very dilute (La, Gd) Al₂ alloys

Resistivity (ρ) measurements on two (La1−xGdx) Al2 samples with x = 700 ppm and 1500 ppm and on a nominally pure LaAl2 sample were made in the normal state between 2 and 8 K. We found that the “reverse resistance anomaly” previously established in this system at higher Gd concentrations seems to become systematically weaker upon dilution of the alloy. This is explained by a completing effect of spurious Ce atoms which are visible in a “Kondo anomaly” of ρ in the nominally pure LaAl2