Magnetic and structural properties of R(Fe1-xCox)9Si2C1.0 (R=Ce, Nd, Sm) compounds

The magnetic and structural properties of the compounds R(Fe1-xCox)9Si2C1.0 (R=Ce, Nd, Sm; x=0.0, 0.1, 0.3, 0.5) were studied. Upon substitution of Co for Fe, the Curie temperature increases, but the magnetization decreases in all compounds. The easy magnetization directions of Ce(Fe1-xCox)9Si2C1.0 and Nd(Fe1-xCox)9Si2C1.0 lie in the basal plane. Sm(Fe1-xCox)9Si2C1.0 compounds have easy-axis anisotropy, and the anisotropy field at 1.5 K increases with increasing Co content. Moreover, a first-order magnetization process is observed at 1.5 K in Nd(Fe1-xCox)9Si2C1.0. Below 120 K, a spin reorientation and a spin-glass-like transition are observed in Nd(Fe1-xCox)9Si2C1.0, and the transition temperature decreases with increasing Co content