A theoretical study of thermal vacancy formation enthalpy of disordered FePt doped by Cu, Zn and Ag

Small-Size Intermetallic FeMnPt Nanoparticles Electrocatalyst for HER Under Acidic and Alkaline Conditions

“…At the same time, the Fe and Mn atoms with a smaller atomic radius than Pt are more likely to overcome the barrier and migrate in the Pt-rich region, which also leads to the formation of the L1 2 -phase rather than the L1 0 -phase. 10,42 Figure 3(a−e) shows the TEM image of intermetallic FeMnPt NPs synthesized by adding different amounts of Mn precursors. The NPs synthesized by the solid-state reaction method are spherical-like and no obvious agglomeration can be found, which indicates that the isolate medium NaCl plays an important role in preventing the sintering of NPs.…”

“…With the increase of Mn precursor addition amounts, the atom ratio of Pt/(Fe + Mn) in intermetallic FeMnPt NPs increases from 1.03 to 1.88, closer to the L 1 2 -phase. At the same time, the Fe and Mn atoms with a smaller atomic radius than Pt are more likely to overcome the barrier and migrate in the Pt-rich region, which also leads to the formation of the L 1 2 -phase rather than the L 1 0 -phase. , …”

“…The s of L 1 0 -FeMnPt NPs increases from 0.88 to 0.90 when adding 5% Mn; the small amount of addition of Mn can facilitate the disorder–order transition. As the melting point of Mn is lower and the surface energy is higher than Fe and Pt, the migration ability of Mn in the FeMnPt lattice is stronger, which may generate some vacancy in the lattice and promote the atomic migration to form the ordered L 1 0 -phase. ,,, The electron spin response has proved to be a reliable method to illustrate vacancy formation . On increasing the Mn addition amount to 10 and 15%, some peaks can be found on the left side of the L 1 0 -(001), (111), (201), and (112) peaks.…”

Effect of the Ag evolution process on ordering the transition for L10-FePt nanoparticles synthesized by Ag addition

“…We also found a small percentage of Ag in the FePt NPs, which is consistent with the results of Chen et al 28 The first-principles study evidenced that the Fe sites are the most energetically favorable positions for Ag substitutional solutes. 44 Thus, a small percentage of Ag atoms should replace Fe sites in the FePt NPs.…”