THE MAGNETIC-PROPERTIES OF R(2)(FE1-XSIX)(17) COMPOUNDS (R=DY, Y)

The structures and magnetic properties of R2(Fe 1-xSix)17 compounds (R=Dy, Y) were investigated by x-ray phase analysis and magnetic measurements. It is shown that Si substitution for Fe leads to a phase transition at x=0.2, and that the mean iron magnetic moment μFe of R2(Fe1-xSi x)17 compounds (R=Dy, Y) decreases as Si concentration x increases; moreover, there is a maximum of dependence Tc(x) at about x=0.16. It is found that the exchange interaction constant AFeFe in R2(Fe1-xSix)17 compounds (R=Dy, Y) increases with x increasing by means of mean-molecular-field analysis of T c. © 1994 American Institute of Physics.