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

The coercivity, time dependent magnetic properties and reversible magnetiza tion behavior for a series of neodymium enriched alloys based on Nd2Fe14B h as been investigated. These studies were carried out in an attempt to eluci date the dramatic increase in the coercivity in these materials with increa sing dilution, of the magnetic phase (Nd2Fe14B). Good correlation between t he coercivity and the relative average linear spacing between magnetic grai ns was found for all but the lowest Nd content. As the Nd content is increa sed the reversible magnetization associated with domain wall pinning decrea ses. At high dilutions the reversible magnetization behavior is consistent with the predictions of a Stoner-Wohlfarth model of an assembly of noninter acting single domain particles. The magnetic viscosity parameter, Lambda, d oes not vary consistently with dilution or coercivity.