Magnetic phase diagram of the mn_x fe_2−x p_1−y si_y system

The phase diagram of the magnetocaloric Mn_x Fe_2−x P_1−y Si_y quaternary compounds was established by characterising the structure, thermal and magnetic properties in a wide range of compositions (for a Mn fraction of 0.3 ≤ x < 2.0 and a Si fraction of 0.33 ≤ y ≤ 0.60). The highest ferromagnetic...

Giant magnetocaloric effect for (Mn, Fe, V)2(P, Si) alloys with low hysteresis

The Fe₂P type Mn–Fe–P–Si alloys exhibit a giant magneto-elastic first-order transition, but the large hysteresis limits their performance. Crystal structure evolution and magnetocaloric performance were investigated by varying the Mn and Fe contents at a constant V substitution of 0.02 in Fe₂P-type (Mn_1.17-xFe...

Lattice dynamics across the magnetic transition in (Mn,Fe)1.95(P,Si)

The lattice dynamics in MnFe0.95Si0.50P0.50 were investigated experimentally using Fe57 nuclear inelastic scattering and inelastic x-ray scattering across the first-order magnetic transition which occurs close to room temperature. The lattice dynamics characterization was supported by a macroscopic magnetic characterization, an x-ray...

Ultra-low Hysteresis in Giant Magnetocaloric Mn_1-xV_xFe_0.95(P,Si,B) Compounds

Large thermal hysteresis in the (Mn,Fe)2(P,Si) system hinders an efficient heat exchange and thus limits the magnetocaloric applications. Substitution of manganese by vanadium in the Mn1-x1Vx1Fe0.95P0.593Si0.33B0.077 and Mn1-x2Vx2Fe0.95P0.563Si0.36B0.077 compounds enable a significant reduction in the thermal hysteresis without losing the giant...

Mixed magnetism in magnetocaloric materials with first-order and second-order magnetoelastic transitions

Temperature dependent high-resolution x-ray diffraction measurements were used to characterize the magneto-elastic ferromagnetic transition of (Fe,Mn)2(P,Si,B) compounds. Across the transition, apart from a change in lattice parameters across the transition, the internal coordinates of Mn and Fe also change. This intrinsic degree of freedom...

Tuning the magneto-elastic transition of (Mn,Fe,V)₂(P,Si) alloys to low magnetic field applications

The first-order magneto-elastic transition in the Mn–Fe–P–Si alloys can be tailored by vanadium substitution. Alloys with a suitable V substitution provide an excellent magnetocaloric effect with minor hysteresis in low magnetic fields up to 1.2 T. Mössbauer measurements show that the hyperfine field is reduced by V substitution. Neutron...

Combined effect of annealing temperature and vanadium substitution for mangetocaloric Mn_1.2-xV_xFe_0.75P_0.5Si_0.5 alloys

Approaching the border of the first order transition and second order transition is significant to optimize the giant magnetocaloric materials performance. The influence of vanadium substitution in the Mn_1.2-xV_xFe_0.75P_0.5Si_0.5 alloys is investigated for annealing temperatures of 1323,...

Reversible low-field magnetocaloric effect in Ni-Mn-In-based Heusler alloys

Ni-Mn-X (X = In, Sn, and Sb) based Heusler alloys show a strong potential for magnetic refrigeration owing to their large magnetocaloric effect (MCE) associated with first-order magnetostructural transition. However, the irreversibility of the MCE under low field change of 0–1 T directly hinders its application as an efficient magnetic coolant....