Partner: Sabina Lewińska

Institute of Physics, Polish Academy of Sciences (PL)

Recent publications
1.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 ( M S ) 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 M S 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
2.Krajewski M., Brzozka K., Tokarczyk M., Kowalski G., Lewinska S., Slawska-Waniewska A., Lin W.S., Lin H.M., Impact of thermal oxidation on chemical composition and magnetic properties of iron nanoparticles, Journal of Magnetism and Magnetic Materials, ISSN: 0304-8853, DOI: 10.1016/j.jmmm.2018.03.047, Vol.458, pp.346-354, 2018
Abstract:

The main objective of this work is to study the influence of thermal oxidation on the chemical composition and magnetic properties of iron nanoparticles which were manufactured in a simple chemical reduction of Fe3+ ions coming from iron salt with sodium borohydride. The annealing processing was performed in an argon atmosphere containing the traces of oxygen to avoid spontaneous oxidation of iron at temperatures ranging from 200 °C to 800 °C. The chemical composition and magnetic properties of as-prepared and thermally-treated nanoparticles were determined by means of X-ray diffractometry, Raman spectroscopy, Mössbauer spectroscopy and vibrating sample magnetometry. Due to the magnetic interactions, the investigated iron nanoparticles tended to create the dense aggregates which were difficult to split even at low temperatures. This caused that there was no empty space between them, which led to their partial sintering at elevated temperatures. These features hindered their precise morphological observations using the electron microscopy techniques. The obtained results show that the annealing process up to 800 °C resulted in a progressive change in the chemical composition of as-prepared iron nanoparticles which was associated with their oxidation. As a consequence, their magnetic properties also depended on the annealing temperature. For instance, considering the values of saturation magnetization, its highest value was recorded for the as-prepared nanoparticles at 1 T and it equals 149 emu/g, while the saturation point for nanoparticles treated at 600 °C and higher temperatures was not reached even at the magnetic field of about 5 T. Moreover, a significant enhancement of coercivity was observed for the iron nanoparticles annealed over 600 °C.

Keywords:

Chemical composition, Chemical reduction, Iron nanoparticle, Magnetic properties, Oxidation

Affiliations:
Krajewski M.-IPPT PAN
Brzozka K.-University of Technology and Humanities in Radom (PL)
Tokarczyk M.-University of Warsaw (PL)
Kowalski G.-University of Warsaw (PL)
Lewinska S.-Institute of Physics, Polish Academy of Sciences (PL)
Slawska-Waniewska A.-Institute of Physics, Polish Academy of Sciences (PL)
Lin W.S.-Tatung University (TW)
Lin H.M.-Tatung University (TW)
3.Krajewski M., Lin W.S., Lin H.M., Brzózka K., Lewińska S., Nedelko N., Ślawska-Waniewska A., Borysiuk J., Wasik D., Structural and magnetic properties of iron nanowires and iron nanoparticles fabricated through a reduction reaction, Beilstein Journal of Nanotechnology, ISSN: 2190-4286, DOI: 10.3762/bjnano.6.167, Vol.6, pp.1652-1660, 2015
Abstract:

The main goal of this work is to study the structural and magnetic properties of iron nanowires and iron nanoparticles, which have been fabricated in almost the same processes. The only difference in the synthesis is an application of an external magnetic field in order to form the iron nanowires. Both nanomaterials have been examined by means of transmission electron microscopy, energy dispersive X-ray spectrometry, X-ray diffractometry and Mössbauer spectrometry to determine their structures. Structural investigations confirm that obtained iron nanowires as well as nanoparticles reveal core–shell structures and they are composed of crystalline iron cores that are covered by amorphous or highly defected phases of iron and iron oxides. Magnetic properties have been measured using a vibrating sample magnetometer. The obtained values of coercivity, remanent magnetization, saturation magnetization as well as Curie temperature differ for both studied nanostructures. Higher values of magnetizations are observed for iron nanowires. At the same time, coercivity and Curie temperature are higher for iron nanoparticles.

Keywords:

iron nanoparticles, iron nanostructures, iron nanowires, magnetic properties, structural properties

Affiliations:
Krajewski M.-other affiliation
Lin W.S.-Tatung University (TW)
Lin H.M.-Tatung University (TW)
Brzózka K.-University of Technology and Humanities in Radom (PL)
Lewińska S.-Institute of Physics, Polish Academy of Sciences (PL)
Nedelko N.-Institute of Physics, Polish Academy of Sciences (PL)
Ślawska-Waniewska A.-other affiliation
Borysiuk J.-University of Warsaw (PL)
Wasik D.-University of Warsaw (PL)
4.Krajewski M., Lin W.S., Lin H.M., Tokarczyk M., Lewińska S., Nedelko N., Ślawska-Waniewska A., Kowalski G., Borysiuk J., Wasik D., High temperature annealing of iron nanowires, PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, ISSN: 1862-6300, DOI: 10.1002/pssa.201431843, Vol.212, No.4, pp.862-866, 2015
Abstract:

This work presents the results of high temperature annealing of iron nanowires at five different temperatures (ranging 200–800 °C) in the slightly oxidative atmosphere. Investigated nanomaterial was prepared in simple chemical reduction process from aqueous solution of iron trichloride placed in external magnetic field. Experimental results allowed determining how magnetic properties of as-prepared as well as annealed iron nanowires change in respect to their structures. They also delivered information about phase transitions occurred in as-prepared sample under thermal treatment.

Keywords:

annealing, iron, magnetic properties, nanowires

Affiliations:
Krajewski M.-other affiliation
Lin W.S.-Tatung University (TW)
Lin H.M.-Tatung University (TW)
Tokarczyk M.-University of Warsaw (PL)
Lewińska S.-Institute of Physics, Polish Academy of Sciences (PL)
Nedelko N.-Institute of Physics, Polish Academy of Sciences (PL)
Ślawska-Waniewska A.-other affiliation
Kowalski G.-University of Warsaw (PL)
Borysiuk J.-University of Warsaw (PL)
Wasik D.-University of Warsaw (PL)
5.Krajewski M., Małolepszy A., Stobiński L., Lewińska S., Ślawska-Waniewska A., Tokarczyk M., Kowalski G., Borysiuk J., Wasik D., Preparation and Characterization of Hematite-Multiwall Carbon Nanotubes Nanocomposite, Journal of Superconductivity and Novel Magnetism, ISSN: 1557-1939, DOI: 10.1007/s10948-014-2794-7, Vol.28, No.3, pp.901-904, 2015
Abstract:

The aim of this work is to study the preparation and characterization of a new nanocomposite which consists of chemically-modified multiwall carbon nanotubes covered by randomly-deposited nanoparticles of hematite. The morphology, structural and physical properties of the investigated nanomaterial were determined by means of transmission electron microscopy, X-ray diffraction and vibrating sample magnetometry at ambient conditions. The presence of residual catalyst nanospheres inside multiwall carbon nanotubes was confirmed by transmission electron microscopy. The signal coming from this contamination was under the detection limit of X-ray diffractometer, therefore it was not registered.

Keywords:

Hematite, Multiwall carbon nanotubes, CVD, TEM, XRD, VSM

Affiliations:
Krajewski M.-other affiliation
Małolepszy A.-Warsaw University of Technology (PL)
Stobiński L.-Warsaw University of Technology (PL)
Lewińska S.-Institute of Physics, Polish Academy of Sciences (PL)
Ślawska-Waniewska A.-other affiliation
Tokarczyk M.-University of Warsaw (PL)
Kowalski G.-University of Warsaw (PL)
Borysiuk J.-University of Warsaw (PL)
Wasik D.-University of Warsaw (PL)

Conference papers
1.Krajewski M., Tokarczyk M., Witecka A., Lewińska S., Ślawska-Waniewska A., Małolepszy A., Liou S.C., Chiou W.A., Manufacturing and magnetic properties of FexCo1‒x wire-like nanoalloys, CNM 2019, 6th CONFERENCE ON NANO- AND MICROMECHANICS, 2019-07-03/07-05, Rzeszów (PL), pp.103-104, 2019
Keywords:

magnetic-field-induced process, magnetic material, nanoalloy, wire-like nanostructure

Affiliations:
Krajewski M.-IPPT PAN
Tokarczyk M.-University of Warsaw (PL)
Witecka A.-IPPT PAN
Lewińska S.-Institute of Physics, Polish Academy of Sciences (PL)
Ślawska-Waniewska A.-other affiliation
Małolepszy A.-Warsaw University of Technology (PL)
Liou S.C.-University of Maryland (US)
Chiou W.A.-University of Maryland (US)

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
2.Krajewski M., Tokarczyk M., Witecka A., Lewińska S., Ślawska-Waniewska A., Liou S.C., Chiou W.A., Płocińska M., Towards magnetic 1D nanostructures - magnetic field as a growth parameter, LIV Zakopane School of Physics Breaking Frontiers: Submicron Structures in Physics and Biology, 2019-05-21/05-25, Zakopane (PL), pp.42-42, 2019