Effect of intergrain exchange interaction on magnetic viscosity of nanocrystalline isotropic NdFeB magnets

The coefficient of magnetic viscosity, S, of NdFeB alloys with varied intergrain exchange interaction constant, K IEI, was measured. The observed dependences of fluctuation field, H f, on the applied field, H, are strongly correlated with K IEI value. Cooperative magnetization reversal of single domain interacting particles leads to improve the temperature stability of permanent magnets and magnetic systems based on them.