Correlation between Fe content and z value in Sm(CobalFexCu0.06Zr0.025)z permanent magnets.

Highlights • The Sm(Co bal Fe x Cu 0.06 Zr 0.025) z magnets with different Fe content and z value were investigated. • The correlation of Fe content and z value was established to achieve excellent magnetic properties. • Increasing Fe content promoted the irreversible microstructure evolution in magnets. • Magnetic domain patterns of magnets affected by increasing Fe content indirectly. Abstract Correlation between Fe content and z value on the structural and magnetic properties of the Sm(Co bal Fe x Cu 0.06 Zr 0.025) z magnets (x = 0.20, 0.25, 0.28, and z = 7, 9.5) has been investigated. It is found that the cellular phases in the magnets grow up with increasing Fe content, so the cell boundary phases could hardly form well without enough Sm atoms, resulting in coercivity decreasing. After supplement of Sm content by decreasing z value, cell boundary phases formed continuously, and coercivity was strongly enhanced due to the remarkable concentration gradient of Cu between the 1:5H cell boundary phase and 2:17R cellular phase. It is thus suggested that as the Fe content increases, the z value of magnets need reducing simultaneously in order to keep high coercivity of the magnets. [ABSTRACT FROM AUTHOR]