Magnetic properties of R(Fe,Mn)11Ti compounds

High‐field magnetization measurements have been performed on both free‐powder samples and magnetically aligned samples of R(Fe,Mn)11Ti (R=Y, Nd, Sm, Gd, Er) compounds at 4.2 K in a step field up to 28 T. The temperature dependence of acsusceptibilities of R(Fe,Mn)11Ti has been measured in a temperature range from 4.2 to 800 K. It has been found that both the magnetic moment of the transition‐metal sublattice and the Curie temperature of RFe11−x Mn x Ti compounds decrease with increasing x. Spin reorientations occur in ErFe11−x Mn x Ti compounds as the result of competition between the uniaxial anisotropy of the transition‐metal sublattice and the planar or conical anisotropy of the Er sublattice. The intersublattice exchange constants n RT of ErFe11−x Mn x Ti compounds have been deduced by the high‐field free‐powder method. The effect of the substitution of Fe by Mn on the magnetic anisotropies of R(Fe,Mn)11Ti with R=Y, Nd, Sm has been investigated. First‐order magnetization processes take place in SmFe11−x Mn x Ti compounds when the external field is applied perpendicular to the alignment direction.