Effects of various chemical synthetic routes on structural and magnetic features of Mn–Pt bimetallic nanoparticles

Mn–Pt nanoparticles were synthesized by ‘wet-chemical’ methods, in various organic solvents and with several combinations between organometallic precursors and capping ligands. The results show that the size of the obtained nanoparticles can be tuned between 2 and 9 nm, through adjustment of the synthetic conditions, including the nature and concentration of the starting reagents and the choice of reaction temperatures. Some of the as-prepared samples present exchange bias features probably due to the simultaneous occurrence of antiferromagnetic MnO and ferrimagnetic Mn3O4 oxides. Magnetic characterization of annealed alloy nanoparticles indicates the co-existence of both superparamagnetic and interacting nanoparticles as well as the presence of two different hard and soft magnetic phases, displaying high coercivity values at 10 K.

Mn–Pt nanoparticles were synthesized by thermal decomposition/reduction method with variation of metal precursors, organic solvents and capping ligands, as 1-adamantanecarboxylic acid (ACA). Depending on the synthetic conditions, monodisperse MnPt3 nanoparticles could be obtained, while in some cases significant oxidation of manganese was observed, together with Pt-rich particles. Regarding the magnetic properties, exchange bias phenomena were assumed in the oxidized samples.Figure optionsDownload as PowerPoint slide