Change in lattice constant along the direction of magnetic moment with the application of a magnetic field induces magnetostriction in materials. At the atomic scale the origin of magnetostriction can be related to the spin-orbit coupling. At the macroscopic scale, the domain reorientation causes dimension change.
TbFe2 has a very large magnetostriction
Other materials are DyFe2, SmFe2, Fe, Ni, FeSi