We have found a complete thermoelastic intermartensitic transformation betw
een modulated and unmodulated martensite in single-crystal Ni52Mn24.5Ga23.5
. This intermartensitic transformation provides a much larger strain than t
hat of the martensitic transformation. A giant switching-like strain of +/-
5.0% can be achieved by a small magnetic field of 0.2 T upon the intermarte
nsitic transformation. In the modulated martensite, a large recoverable mag
netic-field-induced strain of up to 1.2% has been obtained. (C) 2001 Americ
an Institute of Physics.