Magnetic Properties and Domain Structure of Alloy Sm(Co, Fe, Cu, Zr)7.5 in Different Stages of Heat Treatment

The magnetic properties and the changes in the domain structure of alloy Sm(Co, Fe, Cu, Zr)7.5 are studied after different variants of heat treatment, i.e. (1) quenching from 1200°C with cooling in a helium jet; (2) quenching and tempering at 800°C for 16 h, cooling at a rate of 50 K/min to room temperature; and (3) quenching, tempering at 800°C for 16 h, and cooling at a rate of 1.7 K/min. The influence of the heat treatment modes on the coercivity and the domain sizes is determined. The mechanism of variation of these characteristics is analyzed.