Magnetic properties of compounds

The magnetic properties of Gd 3 Co 11 − x Fe x B 4 for 2 ≤ x ≤ 4 have been investigated using 57 Fe Mössbauer spectroscopy. These compounds have a hexagonal Ce 3 Co 11 B 4 type of structure and are ordered ferrimagnetically for 2 ≤ x ≤ 4 at room temperature. The increase in the weighted average 57 Fe hyperfine field for 2 ≤ x ≤ 4 is 19 kOe at room temperature, whose corresponding Fe moment is 0.13 μ B . In Gd 3 Co 7 Fe 4 B 4 the Fe moments at the 2 c , 6i1 and 6i2 sites obtained from the 57 Fe hyperfine fields are 1.4, 1.1 and 0 μ B , respectively and the Fe atom at the 6i2 site has no moment. The weighted average values of the isomer shift decrease with increasing Fe content.