Materials with high magnetostriction

The magnetostrictive properties of cubic Laves phases such as TbFe2, Terfenol D and SmFe2 are summarised. It is shown that SmFe2 can be an interesting candidate as a high magnetostrictive material even in the as cast "dirty" state. Fe-X alloys based on Fe-Ga but also Fe-Al are presented as materials with a medium magnetostriction, however with the big advantage of a magnetically soft material. Generally all nonmagnetic substutional elements which cause an increase of the interatomic distance in the Fe-lattice (such as Ga, Al, Si) cause an increase of the magnetostriction too. In Ni-Ga a reduction of the magnetostriction was found. Another interesting material with high magnetostriction is CoFe2O4 which is cheap, easy to produce and an oxidic material. Here magnetostriction values up to 400 ppm can be achieved by hydrostatic compaction followed by a field annealing.