  A polycrystalline and single-crystal samples of near-stoichiometric Ni2MnGa
alloys have been investigated. It was confirmed that martensite short
crystallographic axis (c-axis) is the easy axis of magnetization. The
reversible reorientation of the easy magnetization direction of martensite
samples after 5% compression is found. The same reversible reorientation of the
easy magnetization direction under applied magnetic field occurs in the
single-crystal samples. The field-induced reorientation of the easy
magnetization direction is accompanied with more than 4% of sample's dimension
change. About the same value of the field-induced strains can be obtained for
polycrystalline samples after appropriate thermo-mechanical treatment.
