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

The nanocrystalline magnetic ribbons of(Nd1-xYx)14.5Feba1B6Co0.2Al1Cu0.15（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(Hcj) decrease from 0.80 to 0.71 T and1400 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.