Mesoscopic structure of Ni2 + xMn1 − xGa alloys in the concentration range corresponding to a coupled magnetic-structural phase stransition

The Ni2 + x Mn1 − x Ga magnetic shape memory alloys at concentrations x = 0.18–0.36 have been studied using small-angle polarized neutron scattering in magnetic fields 0 0.27, the relationship between the characteristic temperatures is changed, i.e., T m > T C. The small-angle polarized neutron scattering data indicate that, in the concentration range under investigation, there occurs a complex transformation of the magnetic and atomic structures. All phase transitions exhibit a temperature hysteresis of scattering and polarization, which is characteristic of first-order phase transitions. A comparative analysis of the mesoscopic structures of the Ni2 + x Mn1 − x Ga and Ni2 + x + y Mn1 − x Ga1 − y alloys studied using the small-angle polarized neutron scattering technique has been carried out.