By: Mario Alberto Annunziata
At: Instituto de Investigação Interdisciplinar, Anfiteatro
Ferrogels are magnetic hybrid systems made of ferromagnetic particles embedded in a polymer matrix, which is then cross-linked. We introduce and investigate a coarse-grained model for quasi one-dimensional ferrogels. Magnetic particles are represented by hard spheres with a magnetic dipole moment in their centers. Harmonic springs mimic the presence of a cross-linked polymer matrix. A special emphasis is put on the coupling of the dipolar orientations to the elastic deformations of the matrix. This system already shows a phase transition between âsoft-elasticâ and âhardenedâ states. In addition, depending on the strength of magneto-mechanical coupling, its phase diagram can exhibit regions of uniaxially ferromagnetic, antiferromagnetic and spirally-magnetized states.