Partner: T. Stefaniuk

University of Warsaw (PL)

Recent publications
1.Krajewski M., Tokarczyk M., Stefaniuk T., Słomińska H., Małolepszy A., Kowalski G., Lewińska S., Ślawska-Waniewska A., Magnetic-field-induced synthesis of amorphous iron-nickel wire-like nanostructures, MATERIALS CHEMISTRY AND PHYSICS, ISSN: 0254-0584, DOI: 10.1016/j.matchemphys.2020.122812, Vol.246, pp.122812-1-7, 2020
Abstract:

Manufacturing process of wire-like binary or ternary metal nanoalloys applying the magnetic-field-induced (MFI) synthesis is still a challenging task. Hence, this work demonstrates for the first time how to produce the iron-nickel wire-like nanostruc-tures with Fe0.75Ni0.25, Fe0.5Ni0.5 and Fe0.25Ni0.75 compositions. In a contrary to the previously reported synthesis of the Fe-Ni wire-like nanomaterials, this process has been carried out at room temperature without employment of templates, surfactants, organic solvents, and other chemical additives. The as-prepared samples exhibit specific structures with the amorphous bimetallic alloy cores covered by thin amorphous oxide shells. Moreover, they are composed of nanoparticles which are aligned in nearly linear chains. The Fe-Ni samples are ferromagnetic materials. Their coercivity values and saturation magnetizations depend on chemical compositions and dimensions of the investigated chains. The highest saturation magnetization and the lowest coercivity is found for the material with the lowest content of nickel and vice versa.

Keywords:

amorphous materials, Fe–Ni chains, magnetic-field-induced synthesis, magnetic materials, wire-like nanostructure

Affiliations:
Krajewski M.-IPPT PAN
Tokarczyk M.-University of Warsaw (PL)
Stefaniuk T.-University of Warsaw (PL)
Słomińska H.-IPPT PAN
Małolepszy A.-Warsaw University of Technology (PL)
Kowalski G.-University of Warsaw (PL)
Lewińska S.-Institute of Physics, Polish Academy of Sciences (PL)
Ślawska-Waniewska A.-other affiliation
2.Krajewski M., Tokarczyk M., Stefaniuk T., Lewińska S., Ślawska-Waniewska A., Thermal treatment of chains of amorphous Fe1–xCox nanoparticles made by magnetic-field-induced coreduction reaction, IEEE Magnetics Letters, ISSN: 1949-307X, DOI: 10.1109/LMAG.2019.2950644, Vol.10, pp.6108405-1-5, 2019
Abstract:

The thermal treatment of chains composed of amorphous Fe 1–x Co x nanoparticles in two different oxygen atmospheres was studied. The nanostructures were manufactured using a magnetic-field-induced coreduction reaction, in which the precursor solutions containing 1:3 and 3:1 proportions of Fe 2+ and Co 2+ ions were reduced with sodium borohydride. The as-prepared nanochains were then heated for 30 min at 400 and 500 °C in dry air or argon containing about 1% oxygen. These processes led to their oxidation, and, as a result, the thermally treated Fe 1–x Co x nanochains were transformed into cobalt ferrite. Heating at 500 °C in the air-containing atmosphere caused the nanomaterials to lose their nanochain structures. In accordance to room-temperature magnetic measurements, the as-prepared and thermally treated Fe 1–x Co x nanochains were ferromagnetic. The highest saturation magnetization (Ms) was measured for the Fe 1–x Co x nanochains treated at 400 °C in dry air (105 A*m^2/kg and 154 A*m^2/kg for Fe 0.25 Co 0.75 and Fe 0.75 Co 0.25, respectively), whereas the lowest Ms was found for the Fe 0.25 Co 0.75 heated at 500 °C in dry air (17 A*m^2/kg) and the Fe 0.75 Co 0.25 heated at 500 °C in argon (16 A*m^2/kg).

Keywords:

nanomagnetics, FeCo nanochains, magnetic-field-induced synthesis, thermal treatment

Affiliations:
Krajewski M.-IPPT PAN
Tokarczyk M.-University of Warsaw (PL)
Stefaniuk T.-University of Warsaw (PL)
Lewińska S.-Institute of Physics, Polish Academy of Sciences (PL)
Ślawska-Waniewska A.-other affiliation

Conference abstracts
1.Krajewski M., Tokarczyk M., Stefaniuk T., Kowalski G., Lewińska S., Ślawska-Waniewska A., High temperature treatment of nanochains composed of Fe1‒xCox nanoparticles, IBCM 2019, III International Baltic Conference on Magnetism: focus on nanobiomedicine and smart materials, 2019-08-18/08-22, Svetlogorsk (RU), pp.52-52, 2019