Effect of the martensite twin structure on the deformation induced magnetic avalanches in Ni2MnGa single crystalline samples

The noise energy versus strain functions, obtained from bending deformation induced magnetic noises, are different for different twin structures of Ni2MnGa single crystals and have two characteristically different stages: unipolar magnetic signals, reflecting the elastic strain induced rearrangement of magnetic domains, as well as bipolar signals, belonging to rearrangements of the martensite variant structure. The critical exponents of the probability density functions of energy and amplitude were larger for samples with highly mobile twin II boundaries than for the other two samples in the bipolar regime. The noise energy is considerably smaller for the motion of twin II boundaries.

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