Chemical synthesis of L1 Fe-Pt-Ni alloy nanoparticles

Abstract

This work focuses on the study of the magnetic and structural properties of chemically synthesized FePt1-xNix nanoparticles, with Ni content x in the range 0.2-0.4. We report the effect of Ni substitution on the L10 structure, on both the as-synthesized and annealed nanoparticles. A decrease in nanoparticle size as well as in chemical order is observed with an increase in Ni content, for both the as-made and annealed nanoparticles. The results also show that the post annealing procedure at 700oC significantly enhanced the L10 ordering of the nanoparticles. Substitution of nickel leads to a decrease in coercivity from 14.9 kOe in FePt to 0.8 kOe for FePt0.6Ni0.4 alloy, while the magnetization at 3 T is increased from 48 emu/g to 88 emu/g.

Structurally Ordered Low‐Pt Intermetallic Electrocatalysts toward Durably High Oxygen Reduction Reaction Activity

“…The PtM 3 (M = Fe, Co, and Ni) NPs were prepared by organic‐phase reduction using organometallic compounds such as Pt(acac) 2 , Fe(acac) 3 , Co(acac) 2 , and Ni(ac) 2 as the metal precursors . As schemed in Figure a, the as‐prepared NPs were then supported on high surface area carbon (Vulcan, XC‐72) and annealed at 180 °C in air first to remove residual surfactants and then 400 °C in Ar/H 2 for 4 h (denoted as PtM 3 ‐H400) to form disordered PtM 3 alloy NPs.…”

“…The synthesis of PtCo 3 and PtCo NPs was performed in a similar way except that 0.58 mmol and 0.3 mmol Co(acac) 2 was used as Co precursor, respectively, and 100 mg TDD was added as the reducing agent. The PtFe 3 NPs were prepared by the method reported Deepchand et al In brief, 0.125 mmol Pt(acac) 2 , 0.375 mmol Fe(acac) 3 , 1 mmol hexadecanediol, and 0.25 mL oleic acid were added in 20 mL trioctylamine and heated at 330 °C for 1 h in Ar. The centrifugation of NPs and mixing with carbon support were conducted in a similar way as described above.…”

Rational Development of Structurally Ordered Platinum Ternary Intermetallic Electrocatalysts for Oxygen Reduction Reaction

“…Synthesis of ternary Pt alloys: The synthesis of ternary Pt-alloy nanoparticles (NPs) was carried out by organic liquid phase reduction methods [32][33][34]. The synthesis of Pt-Ni-Co NPs was carried out according to the following procedure; 0.2 mmol Ni(ac) 2 •4H 2 O, 0.3 mmol Co(ac) 2 •4H 2 O, 50 mg TDD, 0.2 mL OAm, and 0.2 mL OAc were dissolved in 15 mL BE contained in a 50 mL three-necked flask.…”

Atomic Migration and Ordering of Binary Ferromagnetic Intermetallic L10Phases and Influences of Alloying Elements and Electric Fields

“…One occasionally suggested route to achieve an acceleration of the ordering of FeNi from A1 to may be ternary alloying [ 40 ] with an element of a more easily ordering phase, for example, Pt of FePt complementarily to Ni. [ 17,41 ] Following this suggestion, we have studied the atomic migration processes in the ternary Fe–Ni–Pt system. Our goal was to examine how the magnetic properties and the migration energies for atomic jumps are influenced by presumably small amounts of Pt in FeNi.…”