Magnetic properties and structures of Y-substituted Nd–Y–Fe–B melt-spun ribbons

The nanocrystalline magnetic ribbons of (Nd_1−xY_x)_14.5Fe_balB₆Co_0.2Al₁Cu_0.15 (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by melt-spinning technique. The magnetic properties and microstructures were systematically investigated for the ribbons. It is found that Y substituting Nd in the R₂Fe₁₄B main phase grains gives rise to the decrease in the crystal lattice constant. When Y content increases from x = 0 to x = 0.4, the remanence and intrinsic coercivity (H_cj) decrease from 0.80 to 0.71 T and 1400 to 809 kA·m⁻¹, respectively, with the corresponding descent rate of 11.5% and 42.5%. It is impressed that the average grain size increases with Y content increasing. And the strong intergrain exchange coupling interactions exist in all the ribbons and could be enhanced with an appropriate Y substitution, such as x = 0.4. Moreover, magnetization reversal mechanism is confirmed to be pinning type for the ribbons. The results provide valuable reference to the fabrication of Y-substituted Nd–Y–Fe–B sintered magnets.