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Information × Registration Number 0220U100021, 0117U000435 , R & D reports Title Variation of physical properties in ferromagnetic shape memory Heusler alloys under the influence of magnetic field and mechanical stress popup.stage_title Head Kokorin Volodymyr V., Доктор фізико-математичних наукKonopliuk Serhii M., Кандидат фізико-математичних наук Registration Date 03-01-2020 Organization Institute of Magnetism of the National Academy of Sciences of Ukraine and Ministry of Education and Sciences of Ukraine popup.description2  Metamagnetic Heusler alloys are related to shape memory and pseudoelastic alloys. Huge difference in electric resistivity between austenite and martensite is also intrinsic in these alloys. This is accounted for appearance of antiferromagnetism in martensitic phase and, as a result, formation of superzone boundary gap on Fermi surface. Combining these properties record values of resistivity at relatively low applied stresses can be restored after superelastic deformation of polycrystalline samples of Ni-Mn-In-Co. After substantial (7-10%) deformation accompanied by growth of electrical resistance by 2.5-3 times due to stress-induced martensitic transformation, Ni43Mn37.8In12.2Co7 and Ni43Mn37.65In12.35Co7 alloys have demonstrated its full recovery. This was observed after unloading and warming up to the temperatures above reverse martensitic transformation ones due to vanishing deformation martensite formed in the course of sample compression in the areas with elevated stress levels. The fractures of small sizes appear in polycrystalline samples of Ni-Mn-In-Co upon loading by an increase of local stress level along the grain boundaries. It is caused by different orientations of grains in relation of mechanical stress. Microstructural analysis has shown disappearance of stress-induced martensite in the course of restoring warm-up. Cracks formed during compression close up that together with recovery of electric resistivity indicate shape-memory effect in Ni-Mn-In alloys doped with Co. On unloading after compression up to 6 % almost full recovery of the resistivity is observed. Product Description popup.authors Kozlova Larysa Ye. Кокорін Володимир Володимирович Konopliuk Serhii M. popup.nrat_date 2020-04-02 Close