Structure and magnetostriction of RFex (1.6 ⩽ x ⩽ 2.0) and R(Fe1−yTiy)1.8 (y ⩽ 0.2) alloys (RDy0.65Tb0.25Pr0.1)

Structure, Curie temperature and magnetostriction of RFex (1.6 ⩽ x ⩽ 2.0) and R(Fe1−yTiy)1.8 (y ⩽ 0.2) alloys (RDy0.65Tb0.25Pr0.1) have been investigated using optical microscopy, X-ray diffraction, AC initial susceptibility and standard strain gauge techniques. The homogenized RFex alloys are found to be essentially single phase in the range of 1.8 ⩽ x ⩽ 1.85. The second phase is a rare-earth-rich phase when x ⩽ 1.8, and (Dy, Tb, Pr)Fe3 phase when x ⩾ 1.85. X-ray diffraction indicates that the R(Fe1−yTiy)1.8 alloys contain a small amount of Fe2Ti phase when y ⩾ 0.05, which increases with the increment of Ti content. The Curie temperature of R(Fe1−yTiy)1.8 alloys slightly enhances with increasing Ti concentration when y ⩽ 0.05, then remains almost unchanged in the range of 0.05 ⩽ y ⩽ 0.20. The magnetostriction of RFex alloys is improved when x ⩽ 1.80 and reduced by increasing Fe content when x ⩾ 1.85. The magnetostriction of R(Fe1−yTiy)1.8 alloys is lowered by increasing Ti content.