Metamagnetic transition behaviors and dissipation energy at low temperatures of (Ni–Co)50–Mn–Sn alloys under pulsed high magnetic fields

The metamagnetic transition behavior of a series of (Ni–Co) 50 –Mn–Sn alloys with different Co concentrations was systematically investigated using pulsed high magnetic fields at various temperatures. At low temperatures, the equilibrium magnetic field, H 0 , exhibits nearly constant values, and the dissipation energy, E dis , gradually increases with decreasing temperature, similar to those of other Ni–Mn-based alloys. Alloys with a martensite phase having the 4 O structure were found to exhibit greater E dis than those with a martensite phase having the 6 M structure. Moreover, the E dis of the Ni 45.5 Co 3.9 Mn 38.0 Sn 12.6 alloy, in which 4 O and 6 M types coexist, shows a unique temperature dependence, with relatively large values near room temperature and relatively small values at low temperatures. • Metamagnetic transitions at low temperatures in (Ni-Co) 50 -Mn-Sn were investigated. • Pulsed high magnetic fields were used to induce metamagnetic transitions. • Dissipation energy closely links to the crystal structures of the martensite phase.