MEASUREMENT OF MAGNETIC VISCOSITY IN NDFEB

Magnetic viscosity has been investigated in four samples of melt-quenc hed and sintered NdFeB. The irreversible magnetization has been measur ed using two different techniques based on measurements of the DCD rem anence curve and the reversible susceptibility, The difference in the value of Lambda (sometimes known as the fluctuation field H-f) measure d by these two techniques has been related to a new parameter eta whic h describes the dependence of reversible magnetization on irreversible magnetization. The behaviour of eta for the melt-quenched and sintere d samples is compared with the behaviour expected for an idealised Sto ner-Wohlfarth system.