Magnetic properties of R3Co8Sn4 (R=Y,Gd)

The magnetic properties of the intermetallic phases R3Co8Sn4 (R = Y, Gd) are presented. The two compounds order ferro- (Y) and ferri-magnetically (Gd) with transition temperatures of 61.5 and 102.5 K, respectively. In the paramagnetic region, the Y-compound follows the Curie-Weiss law with mu = 0.98 mu(B)/Co and theta(P) = 62.0 K while a more complex behaviour, typical of a ferrimagnetic substance, is observed for Gd,Co,Sn,. The experimental data, analysed in the framework of the molecular field theory, allow to obtain the exchange parameter for the Go-Co (J(Co-Co) = 83k(B)) and of the Gd-Co (J(Gd-Co) = 11k(B)) interactions