Magnetostriction theory of ultrathin nanofilms

The purpose of this work is to present a self-consistent theoretical scheme to fully describe the magnetoelasticity of ultrathin magnetic nanofilms (UTMNFs). The spherical symmetry is lowered to the cylindrical one in nearly two-dimensional UTMNFs. There are some additional elastic and magnetoelastic parameters induced by symmetry lowering have to be reckoned in to model the magnetostriction of UTMNFs rigorously. In this scheme, the magnetostriction strains along and perpendicular to magnetic field direction are derived by using the principle of minimal total free energy. The magnetostriction strain along x direction is usually seen as the magnetic material's magnetostrictive coefficient which can be expanded into Maclaurin series.