Coercivity, time dependence and reversible magnetization in Nd rich Nd-Fe-B alloys

The coercivity, time dependent magnetic properties and reversible magnetization behavior for a series of neodymium enriched alloys based on Nd₂Fe₁₄B has been investigated. These studies were carried out in an attempt to elucidate the dramatic increase in the coercivity in these materials with increasing dilution of the magnetic phase (Nd₂Fe₁₄B). Good correlation between the coercivity and the relative average linear sparing between magnetic grains was found for all but the lowest Nd content. As the Nd content is increased the reversible magnetization associated with domain wall pinning decreases. At high dilutions the reversible magnetization behavior is consistent with the predictions of a Stoner-Wohlfarth model of an assembly of noninteracting single domain particles. The magnetic viscosity parameter, Λ, does not vary consistently with dilution or coercivity