Structure and physical properties of the solid solution Gd 2– x Nd x PdSi 3 ( x = 0, 0.75, 1, 2)

The structural and magnetic properties of Gd 2− x Nd x PdSi 3 ( x = 0, 0.75, 1, 2) have been studied using X-ray diffraction (XRD), exchange bias and magnetization measurements. The end compounds ( x = 0, 2) along with the solid solutions of them are found to crystallize in the hexagonal superstructure having space group P 6/ mmc . The rare-earth (RE) ions are occupying at two different crystallographically inequivalent sites (2 b and 6 h ), which is similar to all ordered members of the RE 2 PdSi 3 series. The absence of chemical phase separation and formation of true solid solutions are confirmed by the XRD analysis. No signature of exchange bias has been observed signifying the absence of coexistence of magnetic phases. The origin of complex magnetic behaviour in Gd 2− x Nd x PdSi 3 is observed due to the separate magnetic ordering and two available crystallographic sites for magnetic ion. The spin-glass behaviour near ferromagnetic transition in Nd 2 PdSi 3 and anomalous bifurcation in zero-field-cooled and field-cooled magnetization curves in Gd 2 PdSi 3 originates from the proximity and overlap of the transition temperatures of the two RE magnetic ions present in two inequivalent sites, and strongly correlated to the interatomic and intra-atomic distances between RE atoms occupying two crystallographic sites.