Magnetic viscosity of Zn-bonded Sm/sub 2/Fe/sub 17/N/sub x/ magnets

Abstract

The magnetic aftereffect of textured Zn-bonded Sm/sub 2/Fe/sub 17/N/sub 2.9/ was investigated using the extraction method for fixed external magnetic fields. A simple fitting procedure was developed in order to determine effectively the viscosity S and the correct type of irreversible susceptibility /spl chisub irr/. There is no proportionality in the polarization dependence of S and /spl chisub irr/ resulting in a strong polarization dependence of the viscosity coefficient S/sub /spl upsi. The variation of the activation volume v with temperature, polarization and magnetic field is explained by a nonhomogeneous distribution of intrinsic properties, e.g. anisotropy constants, due to a nonhomogeneous degree of nitrogenation.< >