2026-04-14T04:33:36Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/195152024-06-18T11:51:14Zcom_2072_452955com_2072_2054col_2072_453063

00925njm 22002777a 4500 dc Deltell, Àlex author Mohamed, Abd El-Moez A. author Álvarez-Alonso, Pablo author Ipatov, Mihail author Andrés González, Juan Pedro author Gonzalez, Juan Antonio author Sánchez Fernández, Tatiana author Zhukov, Atcady author Escoda i Acero, Ma. Lluïsa author Suñol Martínez, Joan Josep author López Antón, Ricardo author 2021-05 Melt-spun ribbons of nominal composition Ni50Mn36-xFexSn14 (x = 0, 2, and 3) were prepared by melt-spinning. The alloys undergo a martensitic transformation from L21 austenite to an orthorhombic 4O martensite on cooling, as determined by X-ray powder diffraction analysis. Replacement of Mn by Fe linearly reduces the characteristic temperatures of the martensitic transformation (the equilibrium temperature decreases from 328 to 285 K) and reduces the Curie temperature of the austenite phase (from 336 to 300 K), whereas the effect of the applied magnetic field on the martensite transition temperatures is negligible. Magnetic measurements (zero-field cooled, ZFC, and field cooled, FC, curves, AC susceptibility measurements) hint the coexistence of two different ferromagnetic martensitic magnetic phases. Moreover, the AC susceptibility measurements and the irreversibility of the ZFC and FC curves point towards the presence of antiferromagnetic and ferromagnetic interactions in the martensitic phase. All samples exhibit spontaneous exchange bias at 2 K, with double-shifted loops, whereas the evolution of the conventional exchange bias with the temperature agrees quite well with the behavior of ferromagnetic regions surrounded by spin-glass regions or with the coexistence of ferromagnetic–antiferromagnetic interactions. Ni50Mn36-xFexSn14 ribbons present a moderate inverse magnetocaloric effect (with a maximum of the magnetic entropy change of 5.7 Jkg−1K−1 for μ0H = 3 T for x = 3). It is worth to note that these materials feature a significant reservoir (up to 44 Jkg−1K−1 for x = 2) of magnetic entropy change, linked to the proximity of the austenitic ferromagnetic transition to the martensitic transformation The support received from the following organizations is gratefully acknowledged: Spanish MINECO, project numbers: MAT2016-75967-P, MCIU-19-RTI2018-094683-B-C52, and PGC2018-099530-B-C31 (MCIU/AEI/FEDER, UE), Principality of Asturias, project number: IDI/2018/000185, and the Universidad de Castilla-La Mancha (Plan Propio de la Universidad de Castilla-La Mancha (FEDER, EU) for the “Grupo de Materiales Magneticos (GMM) ”. We also thank the enlightening discussions with Prof. B. Hernando http://hdl.handle.net/10256/19515 Metalls -- Aliatges Metals -- Alloys Transformacions martensítiques Martensitic transformations Aliatges amb memòria de forma Shape memory alloys Martensitic transformation, magnetic and magnetocaloric properties of Ni–Mn–Fe–Sn Heusler ribbons