“…Considering these arguments, we have recently started the investigation of the RE-Co-Si ternary systems and discovered the intermetallics RE 6 Co 1.67 Si 3 with RE=La, Ce, Nd, Gd, Tb and Dy [5], [6], [7], [8] and [9]. These ternary silicides crystallize in an hexagonal structure [7] deriving from that of the binary compound Gd 6 Co 4.85 [10] and no solid solution between these two last intermetallics was evidenced. The RE 6 Co 1.67 Si 3 compounds exhibit interesting magnetic properties: (i) Gd 6 Co 1.67 Si 3 orders ferromagnetically at 294 K, a Curie temperature comparable to that observed for pure gadolinium and exhibits a reversible second-order magnetic transition inducing a remarkable MCE [6], [11], [12] and [13] and (ii) two successive ferro(ferri)magnetic transitions appear below T C =84 and 186 K for Nd 6 Co 1.67 Si 3 and Tb 6 Co 1.67 Si 3 , respectively [8], [9], [11], [14], [15], [16] and [17].…”