Magnetic Properties of some Cubic Rare-Earth-Iron Compounds of the Type RFe2 and RxY1−xFe2

Magnetic measurements in fields up to 30 kOe and for temperatures between 4.2° and 1000°K have been performed for cubic Laves phase compounds RFe2 (R=Gd, Tb, Dy, Ho, Er, and Y) and RxY1−xFe2 (R=Gd, Tb, and Er). The Curie temperatures and saturation moments at 4.2°K are given. A compensation in the temperature dependence of the magnetization is only observed for the various compounds in a certain range of x values. Conditions for the occurrence of a compensation point are derived. For the compounds RxY1−xFe2 the iron moment remains constant for 0≤x≤0.8. Above x=0.8 the iron moment increases strongly. The variation of the Fe moments with x is discussed in terms of a nonlocalized moment associated with the iron ions. The moments shown by Er and Tb in ErFe2 and TbFe2 are both 8.3 μB. For most of the compounds RFe2 the lattice constants are given.