Magnetic viscosity, susceptibility and fluctuation fields in sintered NdFeB

The magnetic viscosity and irreversible susceptibility of a sample anisotropic sintered NdFeB have been measured using a vibrating sample magnetometer. Measurements confirm the feasibility of the grain boundary pinning coercivity mechanism. Measured as a function of local field, the fluctuation field is found to decrease with an increasing demagnetization field, with a dip at the coercivity. These results are found to agree with a model based on a randomly oriented system of noninteracting uniaxial fine particles.<
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