journal article·2022-05

Size control of cobalt nanoparticles by adjusting the linear carboxylic acid ligand chain length

Aaron C. Johnston-Peck, Joseph B. Tracy

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Abstract

Size control in the synthesis of Co nanoparticles (NPs) through thermolysis of Co 2(CO) 8 is achieved by adjusting the chain length of linear carboxylic acids used as ligands. As the chain length increases, steric effects reduce the reactivity of the carboxylic acids, thereby slowing the nucleation rate. In the subsequent growth phase, completing deposition of Co precursor onto fewer nuclei yields an increased NP size. Oxidation of Co NPs under ambient atmosphere causes formation of an antiferromagnetic CoO shell that can exchange couple to the Co core, resulting in exchange bias. The superparamagnetic blocking temperature ( T B), coercivity ( H C), and exchange shift ( H EB) strongly depend on the size of the NP, and the most pronounced effects of exchange bias are observed for the smallest Co core size.
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Research context

OpenAlex topics: Catalytic Processes in Materials Science · Nanomaterials for catalytic reactions · Copper-based nanomaterials and applications

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (38)

Show source-provided references
1. Nanomagnetism and spin electronics: materials, microstructure and novel properties10.1007/s10853-006-6564-1 ↗
2. Colloidal nanocrystal shape and size control: the case of cobalt10.1126/science.1058495 ↗
3. A solution-phase chemical approach to a new crystal structure of cobalt10.1002/(SICI)1521-3773(19990614)38:12<1788::AID-ANIE1788>3.0.CO;2-2 ↗
4. Nanoparticle conversion chemistry: Kirkendall effect, galvanic exchange, and anion exchange10.1039/C4NR02025A ↗
5. Beating the superparamagnetic limit with exchange bias10.1038/nature01687 ↗
6. Exchange biasing and magnetic properties of partially and fully oxidized colloidal cobalt nanoparticles10.1103/PhysRevB.72.064404 ↗
7. Exchange bias in nanostructures10.1016/j.physrep.2005.08.004 ↗
8. Exchange bias phenomenology and models of core/shell nanoparticles10.1166/jnn.2008.18306 ↗
9. Synthesis of monodisperse cobalt nanocrystals and their assembly into magnetic superlattices (invited)10.1063/1.370357 ↗
10. Colloidal synthesis of nanocrystals and nanocrystal superlattices10.1147/rd.451.0047 ↗
11. The dependence of Co nanoparticle sizes on the ratio of surfactants and the influence of different crystal sizes on magnetic properties10.1007/s00339-004-2713-z ↗
12. Synthesis of hcp-Co nanodisks10.1021/ja027262g ↗
13. Surfactant effects on the shapes of cobalt nanoparticles10.1016/j.matlet.2005.12.057 ↗
14. A new role for surfactants in the formation of cobalt nanoparticles10.1039/b714456c ↗
15. The critical role of surfactants in the growth of cobalt nanoparticles10.1021/la902120e ↗
16. Bulky adamantanethiolate and cyclohexanethiolate ligands favor smaller gold nanoparticles with altered discrete sizes10.1021/nn3003778 ↗
17. Ligand structure determines nanoparticles' atomic structure, metal-ligand interface and properties10.3389/fchem.2018.00330 ↗
18. From hot-injection synthesis to heating-up synthesis of cobalt nanoparticles: observation of kinetically controllable nucleation10.1002/anie.201005600 ↗
19. The structural evolution and diffusion during the chemical transformation from cobalt to cobalt phosphide nanoparticles10.1039/c1jm10337g ↗
20. W.S. Rasband, ImageJ, U.S. National Institutes of Health: Bethesda, MD, 1997–2011.
21. Investigation of the oxide shell forming on ɛ-Co nanocrystals10.1016/j.micron.2007.10.017 ↗
22. Theory, production and mechanism of formation of monodispersed hydrosols10.1021/ja01167a001 ↗
23. Synthesis of monodisperse spherical nanocrystals10.1002/anie.200603148 ↗
24. Ligand effect on the growth and the digestion of Co nanocrystals10.1021/ja044419r ↗
25. Superparamagnetism10.1063/1.2185850 ↗
26. Synthesis, structural order and magnetic behavior of self-assembled ε-Co nanocrystal arrays10.1109/20.951126 ↗
27. Dinega · 2001
28. O'Handley · 2000
29. Synthesis and structural and magnetic characterization of Ni(Core)/NiO(Shell) nanoparticles10.1021/nn900019x ↗
30. Multi-domain structures in spheroidal Co nanoparticles10.1038/s41598-020-67173-5 ↗
31. Exchange anisotropy in oxide passivated Co fine particles10.1063/1.352398 ↗
32. Magnetic properties of monodispersed Co/CoO clusters10.1103/PhysRevB.61.3103 ↗
33. Critical size for exchange bias in ferromagnetic-antiferromagnetic particles10.1063/1.1978977 ↗
34. Defects in CoO in oxidized cobalt nanoparticles dominate exchange biasing and exhibit anomalous magnetic properties10.1103/PhysRevB.74.184434 ↗
35. Exchange bias in magnetic nanoparticle capped with amorphous magnetic shell10.1063/1.3624751 ↗
36. Controlling the exchange bias field in Co core/CoO shell nanoparticles10.1103/PhysRevB.81.195445 ↗
37. Influence of interfacial roughness on exchange bias in core-shell nanoparticles10.1103/PhysRevB.84.092404 ↗
38. Maximizing exchange bias in Co/CoO core/shell nanoparticles by lattice matching between the shell and the embedding matrix10.1021/acs.chemmater.7b00868 ↗