Incommensurate 6M-modulated structure of Ni–Fe–Ga martensite

The crystal structure of the modulated, low-temperature martensitic phase in Ni2.41Fe0.59Ga ferromagnetic shape memory alloy (FSMA) has been determined by Rietveld refinement of neutron powder diffraction data. The structure shows an incommensurate modulated crystal lattice with some analogies with the 7 M modulated martensitic structure found in Ni2Mn1.2Ga0.8 Heusler alloy. The observed type of lattice modulation with q = 0.3521c∗ gives rise to a new type of martensitic crystal structure in the FSMAs.