Magnetic Properties of the Sm(Co0.45Fe0.15Cu0.40)5 Alloy Prepared by Strip Casting

The magnetic properties and phase composition of the Sm(Co 0.45 Fe 0.15 Cu 0.40 ) 5 alloy prepared by the strip-casting technique (the casting of alloy on a water-cooled copper wheel at a velocity of cooling surface of ~1 m/s) are studied. Curves of magnetization of thermally demagnetized starting plates (after strip casting) and plates subjected to low-temperature treatment at 350°С for 120 h and the hysteresis loops were measured in magnetizing fields of up to 140 kOe. It is shown that the magnetization of samples (σ 140 and σ r ) substantially decreases after the annealing; in this case, the coercive force ( j H c ) increases abruptly. It is assumed that the observed regularities of magnetic hardening can be related to the existence of nanosized Cu-enriched areas, within which the antiferromagnetic order in the Sm(Co, Fe, Cu) 5 lattice is realized. These areas in the ferromagnetic phase with the lower copper content can be domain-wall pinning centers.