Magnetic Properties of Some Rare Earth Silicides of the Type RFe2Si2

${\mathrm{RFe}}_2{\mathrm{Si}}_2$ compounds (where $\mathrm{R}\mathrm{\hspace{0.17em}=\hspace{0.17em}}\mathrm{Rare}\hspace{0.17em}\mathrm{Earth}\mathrm{,\hspace{0.17em}}\mathrm{Y}\hspace{0.17em}\mathrm{or}\hspace{0.17em}\mathrm{Th}$ ) crystallize in tetragonal ${\mathrm{BaAl}}_4$ ‐type structure. Magnetic properties of these compounds with R = Y, Tb, Ho and Er have been examined in the temperature range 4.2–950 K. ${\mathrm{TbFe}}_2{\mathrm{Si}}_2$ exhibits a Néel temperature of 5.5 K indicating that the rare earth sublattice orders antiferromagnetically. In ${\mathrm{HoFe}}_2{\mathrm{Si}}_2$ and ${\mathrm{ErFe}}_2{\mathrm{Si}}_2$ , the rare earth sublattice does not order at temperatures down to 4.2 K. The iron sublattice orders magnetically at nearly 800 K in all the compounds investigated. Saturation magnetization studies on ${\mathrm{YFe}}_2{\mathrm{Si}}_2$ indicate partial ordering of iron moments confirming earlier work that a majority of iron atoms are diamagnetic. Crystal field interactions seem to be significant in ${\mathrm{TbFe}}_2{\mathrm{Si}}_2$ .