Tunable magnetocaloric effect in Gd-based glassy ribbons

Abstract

Articles you may be interested inTheoretical description of magnetocaloric effect in the shape memory alloy exhibiting metamagnetic behavior J. Appl. Phys. 119, 013902 (2016) The series of glassy ribbons Gd 60 M 30 In 10 (M ¼ Mn, Co, Ni, Cu) was synthesized by melt-spinning. The change of transition element M in these Gd-based metallic glasses was proven to induce huge variations of the Curie temperature T C , magnetic entropy change peak values DS m peak , and widths at half maximum values of the magnetic entropy change dT. When M is non magnetic (M ¼ Co, Ni, Cu), the samples behave similarly: they display high values of DS m peak (between -6.6 and -8.2 J/kg K in a magnetic field variation of 4.6 T), average dT values (between 77 and 120 K) and no magnetic hysteresis. On the contrary, when M carries a magnetic moment (M ¼ Mn), some irreversibility appears at low temperature, DS m peak is lower (only 3.1 J/kg K for l 0 H ¼ 4.6 T) and the magnetic transition is very large (dT ¼ 199 K for l 0 H ¼ 4.6 T). These features are explained by some antiparallel coupling between Mn atoms randomly located in the metallic glass. This leads to the occurrence of a cluster-glass behavior at low temperature (35 K), following the ferromagnetic transition observed at 180 K when the temperature is decreased. Also, power law fittings of DS m peak and dT versus l 0 H were performed and show that dT is less field dependent than DS m peak . We could then identify an interesting way of improving the refrigeration capacity of the material at low magnetic field.

Magnetocaloric Effect of Amorphous Gd65Fe10Co10Al10X5 (X = Al, Si, B) Alloys

“…According to the thermodynamic theory, the magnetic entropy change caused by the variation of the external magnetic field from 0 to H max is given by Maxwell relation [12] S M = μ 0…”

The Magnetocaloric Effect and Magnetic Refrigeration Near Room Temperature: Materials and Models

“…Amorphization enhances the corrosion resistance of such materials, and the addition of other elements, usually cheaper than RE metals, decreases the materials' total cost (178). Both factors enhance the applicability of the alloys.…”

High-entropy bulk metallic glasses as promising magnetic refrigerants

“…[1][2][3][4] The magnetocaloric effect can be characterized by the field induced entropy change (DS M ) due to the alignment of its magnetic spins that occurs on exposure to an external magnetic field. 5 In the past decades, extensive efforts have been carried out in exploring the materials with excellent MCE, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and some materials with large DS M have been fabricated, such as Mn-Fe-P-As, 3 Ni-Mn-In-(Co), 4 Gd 5 Si 2 Ge 2 , 6 LaFe 11.4 Si 1.6 , 7 and La 0.7 Ca 0.3 MnO 3 . 8 According to the magnetic transition style, the magnetic refrigerants can be divided into two classes, the first order magneto-structural phase transition materials (FOMTM) and second order magnetic phase transition materials (SOMTM).…”

“…8 According to the magnetic transition style, the magnetic refrigerants can be divided into two classes, the first order magneto-structural phase transition materials (FOMTM) and second order magnetic phase transition materials (SOMTM). 2,9 For FOMTM, e.g., Gd 5 Si 2 Ge 2 , the magnetization shows an abrupt variation at magnetic ordering temperature T C , leading to a very narrow and large peak of isothermal magnetic entropy change (DS pk M ). However, the thermal and magnetic hysteresis of the FOMTM makes them not suitable for the application of magnetic refrigeration.…”

“…6 The SOMTM with gradual and continuous magnetization variation near T C , exhibiting broader DS M peaks and absence of thermal and magnetic hysteresis, are currently considered to be the optimal choice as the magnetic refrigerants. 9 As the SOMTM, the glassy materials, especially the rare earth (RE) based bulk metallic glasses (BMGs) have caused wide interests recently. [10][11][12][13][14][15][16][17] Compared to the crystalline alloys, RE-based BMGs manifest large MCE over a much wider temperature range owing to their unique properties associated with the intrinsic amorphous nature, associated with their intrinsic nature, such as the higher electrical resistivity and thus the smaller eddy current heating, high corrosion resistance, outstanding mechanical properties, and high thermally stability, which causes them to be suitable candidates for magnetic refrigerants.…”