Magnetic properties of ErCo4−xFexB compounds

The magnetic properties of ErCo4−xFexB for 1 ≤ x ≤ 4 have been investigated using 57Fe Mössbauer spectroscopy at room temperature. These compounds have the hexagonal CeCo4B type of structure. Mössbauer studies indicate that those samples are ordered magnetically. In ErFe4B, the 57Fe hyperfine fields are 228.8 and 171.3 kOe at the 2c and 6i sites, respectively, whose corresponding Fe moments are 1.53 and 1.14μB, respectively. The increase in the weighted average 57Fe hyperfine field for 1 ≤ x ≤ 4 in ErCo4−xFexB is 23.4 kOe, whose corresponding Fe moment is 0.16μB. The increase in μFe for 1 ≤ x ≤ 4 in ErCo4−xFexB are 0.32 and 0.17μB at the 2c and 6i site, respectively. The values of μFe(2c)/μFe(6i) are between 1.2 and 1.3 for 1 ≤ x ≤ 4 and increase with increasing Fe content. The weighted average values of the isomer shift in ErCo4−xFexB decreases for 1 ≤ x ≤ 4 with increasing Fe content. From the values of quadrupole splitting the Fe atom at the 2c site contributes to the axial anisotropy and that at the 6i site contributes to the planar anisotropy in ErFe4B.