Magnetic viscosity and coercivity analysis in nanocrystalline Sm2Fe15Si2C ribbons

The magnetic viscosity coefficient S, susceptibility and recoil curves were measured by SQUID For nanocrystalline Sm2Fe15Si2C ribbons at temperatures ranging from 50 K to room temperature. It was found that the effect of strong intergrain exchange coupling on S and thermal activation volume in nanocrystalline Sm2Fe15Si2C can no longer be neglected, especially at high temperature. The relation between thermal fluctuation field H-f and coercivity was analyzed according to two phenomenological models. The mechanism of coercivity was mainly controlled by inhomogeneous pinning rather than a pure nucleation of reverse domain.