Magnetostriction is an interaction between the mechanical and magnetic physics, where a magnetic field applied on magnetostrictive material generates the deformation of the material (direct effect), and a stress applied on it changes the material magnetization (inverse effect). In COMSOL Multiphysics, the Magnetostriction interface is constituted of one Solid Mechanics and one Magnetic Fields interface, which are coupled together via a Magnetostriction multiphysics feature. Hence a magnetostriction problem contains solid and magnetic domains, with at least one domain shared by the two physics interfaces and with the magnetostriction coupling defined on it.