“…Up to the present only very few experimental data on the transport properties of this series of compounds have been available. The light RCu 5 compounds (La, Ce, Pr, Nd, Sm, Eu) crystallize in the simple hexagonal structure, while the heavy rare earth (Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) compounds exhibit the hexagonal β CaCu 5 -type structure (P 6/mmm space group) or regular α AuBe 5 -type structure (F 43m space group) [1]. These cubic structures are metastable and at the temperatures over 700…”