Influence of particle pre-orientation on elastomagnetic effect in a composite material of ellipsoidal Ni microparticles in a silicone matrix

The dependence of the elastomagnetic effect on the orientation of Ni ellipsoidal microparticles dispersed in a silicone matrix is investigated. When a volume strain is produced on the composite material in a fixed magnetizing field, the effects of mechanical and magnetic torque are simply modeled and the induced magnetization change can be predicted as a function of the particles pre-orientation. The theoretical predictions are experimentally verified. As a consequence, it is possible to govern the elastomagnetic effect by proper microparticle orientation. PACS 75.80.+q; 75.50.-y; 81.05.Zx