Observation of magnetic-nuclear cross-correlations in Ni-Mn-Ga

Abstract A study of the non-stoichiometric single crystal Ni 49.1 Mn 29.4 Ga 21.5 with small-angle polarized neutron scattering was previously reported. This alloy, with a Curie temperature T C ≈374 K, has a martensitic transition at T m =306 K. A large increase of the SANS intensity takes place on cooling to T m . An increase of the spin–spin correlation radius at zero magnetic field from ∼40 A to ∼400 A was suggested. In this report, we experimentally confirm this assumption by the observation of magnetic-nuclear interference (MNI) for T m T T C . The amplitude ratio of nuclear-to-magnetic scattering does not exceed a few percents. The temperature, field, and q -dependencies of MNI are discussed.