  The electronic structure, magnetism and phase stability of Pt2-xMn1+xGa(x=0,
0.25, 0.5, 0.75, 1) alloys are studied by first-principle calculations. The
calculations reveal that a potential magnetic martensitic transformation can be
expected in all the series. In addition, a large magnetic-field-induced strain
is likely to appear in Pt2-xMn1+xGa(x=0, 0.25, 0.75, 1) alloys. The electronic
structure calculations indicate that the tetragonal phase is stabilized upon
the distortion because of the pseudogap formation at the Fermi Level. The
magnetic structure is also investigated and the total magnetic moment of the
tetragonal phase is a little larger than that of the cubic austenite phase in
all the series.
