dr inż. Marcin Krajewski

Zakład Mechaniki Materiałów (ZMM)
Pracownia Zaawansowanych Materiałów Kompozytowych (PZMK)
stanowisko: asystent
telefon: (+48) 22 826 12 81 wew.: 456
pokój: 144
e-mail: mkraj

Doktorat
2016-09-19Właściwości strukturalne i magnetyczne nanodrutów żelazowych, nanocząstek żelazowych oraz wielościennych nanorurek węglowych pokrytych tlenkami żelaza 
promotor -- prof. dr hab. Dariusz Wasik, UW
1346 
Ostatnie publikacje
1.Węglewski W., Krajewski M., Bochenek K., Denis P., Wysmołek A., Basista M., Anomalous size effect in thermal residual stresses in pressure sintered alumina-chromium composites, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2019.138111, Vol.762, No.138111, pp.1-10, 2019

Streszczenie:

This paper explores an anomalous size effect in thermal residual stresses occurring in the alumina matrix of Al2O3/Cr sintered composite upon varying the particle size of the chromium reinforcement. When a coarse chromium powder (45 µm mean particle size) is used the average residual stress in the alumina phase after cooling is compressive in accordance with the classical Eshelby solution. However, in the case of a fine chromium (5 µm mean particle size) it switches to tension. This effect, detected by photoluminescence piezospectroscopy, is also confirmed by X-ray and neutron diffraction experiments. As the classical micromechanics models are incapable to capture it, a finite element model is developed with the actual composite microstructure being reconstructed from the microtomography images. It is shown by numerical simulations that the anomalous size effect is associated with the complex microstructure of the composite fabricated with the fine chromium powder. It is also pointed out that the temperature dependence of the coefficients of thermal expansion of the matrix and the reinforcement affects the residual stress levels.

Słowa kluczowe:

thermal residual stress; metal-ceramic composites; size effect; microcomputed tomography, finite element analysis

Afiliacje autorów:

Węglewski W.-IPPT PAN
Krajewski M.-IPPT PAN
Bochenek K.-IPPT PAN
Denis P.-IPPT PAN
Wysmołek A.-University of Warsaw (PL)
Basista M.-IPPT PAN
140p.
2.Krajewski M., Liao P.Y., Michalska M., Tokarczyk M., Lin J.Y., Hybrid electrode composed of multiwall carbon nanotubes decorated with magnetite nanoparticles for aqueous supercapacitors, Journal of Energy Storage, ISSN: 2352-152X, DOI: 10.1016/j.est.2019.101020, Vol.26, pp.101020-101020, 2019

Streszczenie:

This work describes a use of a composite nanomaterial which consists of multiwall carbon nanotubes covered by iron oxide nanoparticles as a hybrid electrode in aqueous supercapacitor. The investigated nanomaterial was manufactured in a two-step simple chemical synthesis in which the first step was a functionalization of carbon nanotubes whereas the second one was the deposition of iron oxide. According the morphological and structural characterization, the carbon nanotubes with diameters of 10–40 nm were successfully covered by randomlydispersed magnetite nanoparticles with average diameter of 10 nm. Moreover, the thermogravimetric analysis results indicated that the mass ratio between carbon nanotubes and iron oxide nanoparticles was about 65–35%. The electrochemical performance of studied hybrid electrode was tested in 1M aqueous KCl electrolyte. The highest specific capacitance of 143 F g‒1 was recorded at a discharge current density of 1 A g‒1. The investigated nanomaterial also exhibited excellent cycling stability i.e. 81% retention of the initial capacitance after 3000 cycles.

Słowa kluczowe:

Hybrid electrode, Magnetite, Multiwall carbon nanotube, Nanocomposite, Supercapacitor

Afiliacje autorów:

Krajewski M.-IPPT PAN
Liao P.Y.-Tatung University (TW)
Michalska M.-Łukasiewicz Research Network‒Institute of Electronic Materials Technology (PL)
Tokarczyk M.-University of Warsaw (PL)
Lin J.Y.-Tatung University (TW)
100p.
3.Krajewski M., Węglewski W., Bochenek K., Wysmołek A., Basista M., Optical measurements of thermal residual stresses in alumina reinforced with chromium, JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/1.5083115, Vol.125, No.135104, pp.135104-1-135104-10, 2019

Streszczenie:

This work describes optical measurements of processing-induced thermal residual stresses in an alumina matrix reinforced with chromium particles. This ceramic-metal composite is manufactured by the powder metallurgy method comprising powder mixing in a planetary ball mill and consolidation by hot pressing. Two different chromium powders (5 μm and 45 μm mean particle size) are used, while the average
alumina particle size is kept constant (1 μm). The residual stresses in aluminum oxide are determined by applying two optical methods: photoluminescence piezo-spectroscopy (PLPS) and Raman spectroscopy (RS). Both experimental techniques reveal a chromium size effect in the residual stress measurements. When the fine chromium powder (5 μm) is used, the average residual stress in the ceramic phase is
tensile (unusual effect), whereas for the coarser chromium powder (45 μm) it becomes compressive. The PLPS measurements of the hydrostatic residual stress component in the ceramic phase yield the values of 0.290 and −0.130 GPa for samples with 5 μm and 45 μm chromium powders, respectively. In the RS experiments, the corresponding stress component in the alumina equals 0.351 GPa for the composite with 5 μm chromium and −0.158 GPa for that with 45 μm chromium powder. These values indicate that the residual stress in the alumina reinforced with 5 μm chromium is approximately twice higher than that in the alumina reinforced with 45 μm chromium. Finally, the validity of the results obtained with the optical techniques is confirmed by the neutron diffraction measurements.

Afiliacje autorów:

Krajewski M.-IPPT PAN
Węglewski W.-IPPT PAN
Bochenek K.-IPPT PAN
Wysmołek A.-University of Warsaw (PL)
Basista M.-IPPT PAN
70p.
4.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

Streszczenie:

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.

Słowa kluczowe:

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

Afiliacje autorów:

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)
30p.
5.Brzózka K., Krajewski M., Szumiata T., Górka B., Gawroński M., Kaczor T., Lin W.S., Lin H.M., Phase Evolution of Iron Nanoparticles Subjected to Thermal Treatment, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.134.1015, Vol.134, No.5, pp.1015-1020, 2018

Streszczenie:

Magnetic nanoparticles based on iron or iron oxides represent an excellent nanomaterial in respect of their fundamental research as well as numerous applications. This work presents a Mössbauer study of the influence of thermal treatment on the structure and phase composition of iron nanoparticles fabricated via a simple reduction reaction. Identification of iron-containing phases has been carried out for the series of samples annealed at different temperatures ranging between 200 C and 800 C. Both crystalline and amorphous iron as well as variety of iron oxides have been detected. It has been proved that the nanoparticles annealed at 500 C show superparamagnetic behavior as a result of ultrafine sizes of crystallites of iron oxides that arise in the oxidation processes.

Afiliacje autorów:

Brzózka K.-University of Technology and Humanities in Radom (PL)
Krajewski M.-IPPT PAN
Szumiata T.-other affiliation
Górka B.-other affiliation
Gawroński M.-other affiliation
Kaczor T.-University of Technology and Humanities in Radom (PL)
Lin W.S.-Tatung University (TW)
Lin H.M.-Tatung University (TW)
15p.
6.Krajewski M., Lee P.H., Wu S.H., Brzózka K., Małolepszy A., Stobiński L., Tokarczyk M., Kowalski G., Wąsik D., Nanocomposite composed of multiwall carbon nanotubes covered by hematite nanoparticles as anode material for Li-ion batteries, Electrochimica Acta, ISSN: 0013-4686, DOI: 10.1016/j.electacta.2017.01.051, Vol.228, pp.82-90, 2017

Streszczenie:

This work describes the detailed studies performed on the nanocomposite composed of chemically-modified multiwall carbon nanotubes covered by hematite nanoparticles which diameters vary from 10 nm to 70 nm. This nanomaterial was fabricated in two-steps facile chemical synthesis and was characterized with the use of several experimental techniques, such as: thermogravimetric analysis, differential thermal analysis, Raman spectroscopy, X-ray diffraction, and transmission Mössbauer spectroscopy in order to determine its structure precisely. Moreover, the investigated nanocomposite was tested as an anode material of Li-ion batteries. Its cycling performance was stable during 40 cycles, while its capacity was retained at the level of 330 and 230 mAh/g at the discharge/charge rate of 25 and 200 mA/g, respectively.

Słowa kluczowe:

anode material, hematite, Li-ion battery, multiwall carbon nanotube, nanocomposite

Afiliacje autorów:

Krajewski M.-IPPT PAN
Lee P.H.-Tatung University (TW)
Wu S.H.-Tatung University (TW)
Brzózka K.-University of Technology and Humanities in Radom (PL)
Małolepszy A.-Warsaw University of Technology (PL)
Stobiński L.-Warsaw University of Technology (PL)
Tokarczyk M.-University of Warsaw (PL)
Kowalski G.-University of Warsaw (PL)
Wąsik D.-other affiliation
40p.
7.Krajewski M., Magnetic-field-induced synthesis of magnetic wire-like micro- and nanostructures, NANOSCALE, ISSN: 2040-3364, DOI: 10.1039/c7nr05823c, Vol.9, No.43, pp.16511-16545, 2017

Streszczenie:

A lot of physical and chemical preparation methods of one-dimensional (1D) structures are known today. Most of them use highly advanced technology or quite complex chemical reagents. This results in their high costs and difficulties with their implementation to a large industrial scale. Hence, new, facile and inexpensive approaches are still sought. One alternative to wire-like structure production is based on the chemical reduction reactions combined with an external magnetic field, which acts as an independent synthesis parameter. This approach is commonly called magnetic-field-assisted (MFA) synthesis or magnetic-field-induced (MFI) synthesis. As usual, this manufacturing strategy comprises both drawbacks and advantages, which are introduced in this review. Moreover, this work shows that MFI synthesis depends on several synthesis parameters including the strength of the applied magnetic field, reaction temperature, pH value of the reaction environment, chemical composition of the precursor solution, reaction time, and also the presence of surfactants, complexing agents, nucleating agents, initiators as well as organic solvents. All of them have an impact on the morphology and dimensions of wire-like materials and their chemical, physical and mechanical properties. Finally, the opportunities and challenges associated with the magnetic-assisted fabrication of wire-like structures are widely discussed in this review

Słowa kluczowe:

magnetic-field-induced synthesis, nanowire, microwire, nanochain, nanostructure, one-dimensional nanostructures

Afiliacje autorów:

Krajewski M.-IPPT PAN
40p.
8.Brzózka K., Krajewski M., Małolepszy A., Stobiński L., Szumiata T., Górka B., Gawroński M., Wasik D., Phase Analysis of Magnetic Inclusions in Nanomaterials Based on Multiwall Carbon Nanotubes, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.131.863, Vol.131, No.4, pp.863-865, 2017

Streszczenie:

Functionalized multiwall carbon nanotubes as well as nanocomposite based on that material covered by nanoparticles composed of iron oxides were the subject of investigations. In order to identify all iron-bearing phases including those reported on the base of previous X-ray diffraction measurements, the transmission Mössbauer spectroscopy was utilized. The experiments were carried out both at room temperature and also at low temperatures. It was stated that in the investigated nanotubes some impurities were present, originating from the catalyst remains, in form of Fe–C and -Fe nanoparticles. The Mössbauer spectra collected for the nanocomposite showed a complex shape characteristic of temperature relaxations. The following subspectra related to iron-based phases were identified: sextet attributed to hematite, with hyperfine magnetic field reduced due to the temperature relaxations, sextet corresponding to iron carbide as well as two doublets linked to superparamagnetic hematite and ferrihydrites.

Słowa kluczowe:

Mossbauer spectroscopy, multiwall carbon nanotubes, phase transition

Afiliacje autorów:

Brzózka K.-University of Technology and Humanities in Radom (PL)
Krajewski M.-other affiliation
Małolepszy A.-Warsaw University of Technology (PL)
Stobiński L.-Warsaw University of Technology (PL)
Szumiata T.-other affiliation
Górka B.-other affiliation
Gawroński M.-other affiliation
Wasik D.-University of Warsaw (PL)
15p.
9.Krajewski M., Brzózka K., Lin W.S., Lin H.M., Tokarczyk M., Borysiuk J., Kowalski G., Wasik D., High temperature oxidation of iron–iron oxide core–shell nanowires composed of iron nanoparticles, Physical Chemistry Chemical Physics, ISSN: 1463-9076, DOI: 10.1039/c5cp07569f, Vol.18, pp.3900-3909, 2016

Streszczenie:

This work describes an oxidation process of iron–iron oxide core–shell nanowires at temperatures between 100°C and 800°C. The studied nanomaterial was synthesized through a simple chemical reduction of iron trichloride in an external magnetic field under a constant flow of argon. The electron microscopy investigations allowed determining that the as-prepared nanowires were composed of self-assembled iron nanoparticles which were covered by a 3 nm thick oxide shell and separated from each other by a thin interface layer. Both these layers exhibited an amorphous or highly-disordered character which was traced by means of transmission electron microscopy and Mössbauer spectroscopy. The thermal oxidation was carried out under a constant flow of argon which contained the traces of oxygen. The first stage of process was related to slow transformations of amorphous Fe and amorphous iron oxides into crystalline phases and disappearance of interfaces between iron nanoparticles forming the studied nanomaterial (range: 25–300°C). After that, the crystalline iron core and iron oxide shell became oxidized and signals for different compositions of iron oxide sheath were observed (range: 300–800°C) using X-ray diffraction, Raman spectroscopy and Mössbauer spectroscopy. According to the thermal gravimetric analysis, the nanowires heated up to 800°C under argon atmosphere gained 37% of mass with respect to their initial weight. The structure of the studied nanomaterial oxidized at 800°C was mainly composed of α-Fe2O3 (∼93%). Moreover, iron nanowires treated above 600°C lost their wire-like shape due to their shrinkage and collapse caused by the void coalescence.

Słowa kluczowe:

annealing, core-shell nanostructure, iron nanoparticles, iron nanowires, oxidation, thermal treatment

Afiliacje autorów:

Krajewski M.-other affiliation
Brzózka K.-University of Technology and Humanities in Radom (PL)
Lin W.S.-Tatung University (TW)
Lin H.M.-Tatung University (TW)
Tokarczyk M.-University of Warsaw (PL)
Borysiuk J.-University of Warsaw (PL)
Kowalski G.-University of Warsaw (PL)
Wasik D.-University of Warsaw (PL)
40p.
10.Krajewski M., Gołasa K., Wasik D., Influence of Iron Nanowires Oxidation on Their Semiconducting Properties, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.129.A-135, Vol.129, No.1-A, pp.A-135-137, 2016

Streszczenie:

The main aim of this work was to study the impact of thermal annealing on the structure of iron oxide shell covering iron nanowires in relation to their semiconducting properties. Studied nanomaterial has been produced via a simple chemical reduction in an external magnetic field and then it has been thermally-treated at 400oC, 600oC and also 800oC in a slightly oxidizing argon atmosphere. Annealed iron nanowires have been characterized by means of the Raman spectroscopy and photoluminescence in order to study the structure of iron oxide shell and its influence on semiconducting properties of the whole nanostructure. According to obtained experimental results, the composition of iron oxide shell covering the studied nanomaterial is changing with annealing temperature. The thermal treatment at 400oC leads to oxidation of iron coming from the core of nanomaterial and formation of a mixture of Fe3O4 and a-Fe2O3 on the surfaces of nanowires, while annealing at higher temperatures results in further oxidation of iron as well as the phase transformation of previously created Fe3O4 into the most thermo-dynamically stable form of iron oxide at ambient conditions — a-Fe2O3. This oxide has a major impact on the semiconducting properties of studied nanomaterial. Thereby, the measurements of photoluminescence enabled to estimate the bandgap of bulk and surface layer at about 1.8 eV and 2.1 eV, respectively.

Słowa kluczowe:

nanowires, structure, optical properties, semiconductor nanostructures, micro- and nano-oxidation

Afiliacje autorów:

Krajewski M.-other affiliation
Gołasa K.-other affiliation
Wasik D.-University of Warsaw (PL)
15p.
11.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

Streszczenie:

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.

Słowa kluczowe:

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

Afiliacje autorów:

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)
35p.
12.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

Streszczenie:

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.

Słowa kluczowe:

annealing, iron, magnetic properties, nanowires

Afiliacje autorów:

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)
25p.
13.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

Streszczenie:

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.

Słowa kluczowe:

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

Afiliacje autorów:

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)
15p.
14.Krajewski M., Brzózka K., Górka B., Lin W.S., Lin H.M., Szumiata T., Gawroński M., Wasik D., The influence of thermal annealing on structure and oxidation of iron nanowires, NUKLEONIKA. INTERNATIONAL JOURNAL OF NUCLEAR RESEARCH, ISSN: 0029-5922, DOI: 10.1515/nuka-2015-0004, Vol.60, No.1, pp.87-91, 2015

Streszczenie:

Raman spectroscopy as well as Mössbauer spectroscopy were applied in order to study the phase composition of iron nanowires and its changes, caused by annealing in a neutral atmosphere at several temperatures ranging from 200°C to 800°C. As-prepared nanowires were manufactured via a simple chemical reduction in an external magnetic field. Both experimental techniques proved formation of the surface layer covered by crystalline iron oxides, with phase composition dependent on the annealing temperature (Ta). At higher Ta, hematite was the dominant phase in the nanowires.

Słowa kluczowe:

amorphous iron and iron oxides, iron nanowires, Mössbauer spectroscopy, Raman spectroscopy, thermal annealing

Afiliacje autorów:

Krajewski M.-other affiliation
Brzózka K.-University of Technology and Humanities in Radom (PL)
Górka B.-other affiliation
Lin W.S.-Tatung University (TW)
Lin H.M.-Tatung University (TW)
Szumiata T.-other affiliation
Gawroński M.-other affiliation
Wasik D.-University of Warsaw (PL)
15p.

Prace konferencyjne
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

Słowa kluczowe:

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

Afiliacje autorów:

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)
2.Liou S.C., Krajewski M., Chiou W.A., Tokarczyk M., Kowalski G., TEM Studies of Fe1-xNix Nanowires by Magnetic-Field-Induced Synthesis , M&M 2019, Microscopy & Microanalysis 2019, 2019-08-04/08-08, Portland (US), DOI: 10.1017/S143192761901170X, No.25, pp.2194-2195, 2019
3.Kruglenko E., Krajewski M., Tymkiewicz R., Litniewski J., Gambin B., Magnetic and ultrasonic thermal effects of magnetic nanoparticles in a tissue phantom, Applications of Electromagnetics in Modern Techniques and Medicine (PTZE) , XXIX Sympozjum PTZE, Zastosowania elektromagnetyzmu we współczesnej inżynierii i medycynie, 2019-06-09/06-12, Janów Podlaski, Polska (PL), DOI: 10.23919/PTZE.2019.8781747, pp.89-92, 2019

Streszczenie:

The aim of the paper was a preliminary comparison of heating efficiency by the two physically different modalities, namely ultrasound sonication and alternating magnetic field, of magnetic nanoparticles added to an agar-gel. Special agar-based tissue mimicking material (TMM) were manufactured from agar with the addition of produced by us iron oxide magnetic nanoparticles of order c/a 11 nanometers. To perform comparison of heating by the measured temperature rise curves caused by the two physical fields differently acting on the material sample, in the case of ultrasonic radiation we did not locate the sensor of thermometer in the ultrasonic beam focus, as it was usually studied, but we put it in the place where distribution of ultrasound intensity was more homogeneous. It was motivated by the fact that the “homogeneous heating” by the magnetic iron oxide nanoparticles which are spatially homogeneously distributed should be compared with the ultrasonic heating effects caused by the spatially homogeneous ultrasonic sources. The obtained results confirm that for both fields, ultrasound and magnetic, the temperature increase was caused by the presence of nanoparticles. In the case of heating by magnetic field pure agar-gel was not heated at all, and during sonication the pure agar-gel exhibited very small thermal effect, due only to the structure of the agar-gel crosslinking. We concluded that the ultrasonic absorption was in our experiment greater than magnetic, but the temperature rise after 180 s of magnetic field action was greater than of sonication.

Słowa kluczowe:

Heating systems, Ultrasonic imaging, Temperature measurement, Acoustics, Magnetic fields, Nanoparticles, Ultrasonic variables measurement

Afiliacje autorów:

Kruglenko E.-IPPT PAN
Krajewski M.-IPPT PAN
Tymkiewicz R.-IPPT PAN
Litniewski J.-IPPT PAN
Gambin B.-IPPT PAN

Abstrakty konferencyjne
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., Magnetic-field-assisted synthesis of iron-based wire-like nanostructures, IMSNC-2019, 2nd International Conference on Material Science and Nanotechnology, 2019-07-15/07-17, London (GB), pp.48-48, 2019
3.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
4.Węglewski W., Basista M., Krajewski M., Bochenek K., An unusual grain size effect in measurements of thermal residual stress in alumina-chromium composites – explanation by modelling, 8th KMM-VIN Industrial Workshop: Modelling of composite materials and composite coatings, 2018-10-09/10-10, Freiburg (DE), pp.22, 2018
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