Mesostructural origin of the field-induced pseudo-plasticity effect in a soft magnetic elastomer

Abstract

A model is presented to studying the pseudo-plasticity effect in a soft magnetic elastomer: a weakly-linked polymer matrix filled with micron-size particles of a ferromagnet with virtually zero coercivity (e.g., iron carbonyl). If the filling fraction of the composite is sufficiently high, such a material displays a remarkable ability to radically change its rheological behavior: being subjected to external magnetic field, the sample loses its elasticity and responds to external mechanical load as if being made of a ductile substance with no tendency to restore its initial shape. In our simulations we show that, considering the system at the mesoscopic scale (as an assembly of particles embedded in an elastic continuum) and taking into account just the magnetostatic and elastic interactions, one is able to qualitatively correct reproduce the field-induced pseudo-plasticity effect.