Magnetoelastic transition and negative thermal expansion of Fe₂Hf_0.83Ta_0.17 ribbons

In this work, the magnetocaloric effect and negative thermal expansion in melt-spun Fe₂Hf_0.83Ta_0.17 Laves phase alloys were studied. Compared to arc-melted alloys, which undergo a first-order magnetoelastic transition from the ferromagnetic to the antiferromagnetic phase, melt-spun alloys exhibit a second...

Exploring the negative thermal expansion and magnetocaloric effect in Fe₂(Hf,Ti) Laves phase materials

The transition-metal based Laves phase materials represent an extended family of alloys with rich and fascinating physical properties. In this work, we have investigated the negative thermal expansion and magnetocaloric effect in arc-melted and melt-spun Fe₂Hf_1-_xTi_x (x = 0.15, 0.27, 0.30, 0.33, 0.36...

Magnetocaloric effect in the (Mn,Fe)₂(P,Si) system: From bulk to nano

In the field of nanoscale magnetocaloric materials, novel concepts like micro-refrigerators, thermal switches, microfluidic pumps, energy harvesting devices and biomedical applications have been proposed. However, reports on nanoscale (Mn,Fe)₂(P,Si)-based materials, which are one of the most promising bulk materials for solid-state...

Effect of Co and Ni doping on the structure, magnetic and magnetocaloric properties of Fe-rich (Mn,Fe)₂(P,Si) compounds

The effect of Co and Ni doping on the structure, magnetic and magnetocaloric properties of Fe-rich (Mn,Fe)₂(P,Si) compounds was studied. With increasing Co and Ni content, both the Curie temperature (T_c) and the thermal hysteresis (ΔT_hys) decreased, whereas the hexagonal P-62 m crystal structure was maintained...

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...

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...

Kinetic-arrest-induced phase coexistence and metastability in (Mn,Fe)2(P,Si)

Neutron diffraction, Mössbauer spectroscopy, magnetometry, and in-field x-ray diffraction are employed to investigate the magnetoelastic phase transition in hexagonal (Mn,Fe)2(P,Si) compounds. (Mn,Fe)2(P,Si) compounds undergo for certain compositions a second-order paramagnetic (PM) to a spin-density-wave (SDW) phase transition before further...