Magnetostriction of terbium alone is confined to the realm of cryogenic temperatures. Dysprosium reduces magnetic field requirements while iron raises the operating temperature and gives strength.

"Standard" commercially available terfenol-d optimizes performance at ocean temperatures. Slight adjustments to the ratio of terbium to dysprosium may be desirable for best temperature performance in a particular application.









Magnetostrictive strain of terfenol-d depends on its temperature. Displacement will decrease with increasing temperature but is fully restored once the rod cools. The downward slopes of strain intersect the horizontal axis at 357C which is terfenol-d's Curie temperature.

Sources

Giant Magnetostriction Materials From Cryogenic Temperatures To 250 C

RARE EARTHS Resources, Science, Technology and Applications Edited by Renato G. Bautista and Norton Jackson The Minerals, Metals & Materials Society 1991, pp 225-238