The permanent magnetic properties of Sm2Fe15−xCoxSi2C (x=0–5) with additional Cu

The effect of Co substitution for Fe on the structure and magnetic properties of Cu doped Sm2Fe15−xCoxSi2C (x=0–5) compounds with the Th2Zn17 structure have been investigated. The substitution of Co leads to a contraction of the unit-cell. The Co content dependence of saturation magnetization Ms exhibits a maximum value of 114.1 emu/g at x=4. The Curie temperature TC increases monotonically with increasing Co concentration from 567 K for x=0 to 723 K for x=5. The room temperature anisotropy field HA is found to slightly decrease with increasing Co content. The intrinsic coercivity of melt-spun Cu doped Sm2Fe15CoxSi2C (x=0–5) ribbons decreases as the Co content is increased. A remanence of 6.23 kG and a maximum energy product of 7.2 MG Oe at room temperature is obtained in the sample of x=3. The coercivity mechanism for melt-spun ribbons is mainly controlled by the nucleation of reverse domains.