2022 journal article
Size control of cobalt nanoparticles by adjusting the linear carboxylic acid ligand chain length
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 550.
author keywords: Magnetic nanoparticles; Cobalt; Cobalt oxide; Carboxylic acids
UN Sustainable Development Goal Categories
3. Good Health and Well-being
(Web of Science)
Source: Web Of Science
Added: May 2, 2022
Size control in the synthesis of Co nanoparticles (NPs) through thermolysis of Co2(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 (TB), coercivity (HC), and exchange shift (HEB) strongly depend on the size of the NP, and the most pronounced effects of exchange bias are observed for the smallest Co core size.