Impact of W doping on Fe-rich (Mn,Fe)2(P,Si) based giant magnetocaloric materials

The synthesis of W–Ni3S2/NiS nanosheets with heterostructure as a high-efficiency catalyst for urea oxidation

“…In Fig. 3a, the peaks at 35.14 eV and 37.48 eV could correspond to W 4f 7/2 and W 4f 5/2 of W–Ni 3 S 2 /NiS, respectively, 52,53 which is attributed to W 6+ . Ni plays an important role in electrocatalysis; in Fig.…”

“…The measured XPS spectra in Fig.S3a† show the presence of the elements Ni, S, and W in the target sample. In Fig.3a, the peaks at 35.14 eV and 37.48 eV could correspond to W 4f 7/2 and W 4f 5/2 of W-Ni 3 S 2 /NiS, respectively,52,53 which is attributed to W 6+ . Ni plays an important role in electrocatalysis; in Fig.3b, for W-Ni 3 S 2 /NiS, the peaks at 855.47 eV and 856.95 eV and their corresponding satellite peaks are attributed to the Ni 2p 3/2 orbit,54,55 while the…”

Advanced Magnetocaloric Materials for Energy Conversion: Recent Progress, Opportunities, and Perspective

“…found that W and Ta substitution can act as a good strategy to solely regulate T C and effectively maintain (or improve) the GMCE property without an increase in Δ T hys . [ 164,165 ] As described earlier, interestingly, F, which possesses the highest electronegativity value among the elements, influences the metal–metalloid system differently (increased Δ T hys and magnetic moments) compared with B (low electronegativity). [ 153 ] The results can further help us understand the role of the electrons for this itinerant‐electron metamagnet.…”

“…Figure 6b, lists the reported dopants for (Mn,Fe) 2 (P,Si) based MCMs so far. [133,136,[151][152][153][154][155][156][157][158][159][160][161][162][163][164][165] For example, Guillou et al [136] pointed out that B substitution with limited concentration can efficiently decrease the ∆T hys from 75 to only 1.6 K. Most importantly, the modified materials show good mechanical properties and excellent reversibility of GMCE after 10 000 cycles of magnetization/demagnetization (ΔT cyclic ≈ 2.8 K with only ∆μ 0 H of 1.1 T). It was found that V, Nb, and Mo substitution can also reduce the hysteresis of (Mn,Fe) 2 (P,Si) based MCMs, which is important as it is known that hysteresis will significantly degrade the energy efficiency of these materials in devices.…”

“…Figure 6b, lists the reported dopants for (Mn,Fe) 2 (P,Si) based MCMs so far. [ 133,136,151–165 ] For example, Guillou et al. [ 136 ] pointed out that B substitution with limited concentration can efficiently decrease the ∆T hys from 75 to only 1.6 K. Most importantly, the modified materials show good mechanical properties and excellent reversibility of GMCE after 10 000 cycles of magnetization/demagnetization (Δ T cyclic ≈ 2.8 K with only ∆µ 0 H of 1.1 T).…”