  In order to obtain modulated-martensite in our epitaxial Ni-Mn-Ga films, we
have tuned the composition by using a co-sputtering process. Here we present
how the composition affects the variant distribution of the 14-modulated
martensite at room temperature. The nature of such modulated-martensites is
still strongly debated for magnetic shape memory alloys. It has been very
recently demonstrated that the modulated-martensites in Ni-Mn-Ga are adaptive
phases. The results presented here corroborate this theory for the first time,
for three different compositions. Moreover, we demonstrate with the help of the
adaptive modulations theory that b-variants of the 14-modulated martensite form
close to the free-surface of the film to release the stress induced by
branching of macro-twinned domains during the martensitic transformation on a
rigid substrate. At room temperature, the content of such b-variants is found
to strongly decrease when the macro-twinned domain sizes increase.
