Effects of high Fe substitution for Mn on phase transition and magnetic properties of YFexMn12−x compounds

► High Fe concentration lead the crystal phase change from ThMn12-type to Th2Zn17-type. ► ThMn12-type YFexMn12−x compounds that has optimal magnetic properties with Fe substitution x=8.8. ► Saturation magnetization and the Curie temperature monotonically increase with Fe substitution.