New NdRuSi2-type structure compounds have been observed in R-Fe-Si systems
(R=Nd, Sm, Gd, To) and in Nd(Co1-xFex)Si-2 solid solution (0 less-than x le
ss than or equal to 1). These new compounds complete the systematics of R-F
e-Si systems around the 1:1:2 composition. Their occurrence is discussed an
d analyzed on the basis of theoretical studies. (C) 1999 Elsevier Science S
.A. All rights reserved.