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The structural features of the amorphous C14 HfNiAl Laves phase

Mudry S. I., Shved O. V., Kulyk Yu.O., Bulyk I. I., Borysiuk A. K.

Archives of Materials Science and Engineering

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2018

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Vol. 89, nr 2

49--54

EN

Purpose: In order to clarify whether amorphization occurs in the pseudo-binary C14 HfNi0.6Al1.4 Laves phase a detailed investigation of the effect of hydrogen treatment on it phase-structural state has been studied. This type of compounds is of interest due to their high possibility to hydrogen absorption as Laves phase structures and as Hf-Ni alloys. Design/methodology/approach: We used a combination of hydrogen treatment and grinding methods for studying of the processes of controlled structure formation. High temperature transformations of the HfNi0.6Al1.4 alloy were pointed out by means of XRD analysis. Findings: By combination of two amorphization methods and high temperature measurements we have observed a phase structural transformation of the HfNi0.6Al1.4 alloy, which could be presented as: HfNi0.6Al1.4(cryst.) + H2 ® HfNi0.6Al1.4 (nanocryst.) + HfNi0.6Al1.4 (amorphous) + H2 ® HfH2 (amorphous) + AlH3 (amorphous) + Ni. Ferromagnetic- like properties of the pseudo-binary HfNi0.6Al1.4 Laves phase was found. Research limitations/implications: Complex research of HfNi0.6Al1.4 alloy revealed various structure features depending on phase content, thermodynamic parameters and conditions of hydrogen treatment. Obtained results suppose that further studies of structure and physical properties of Hf-Ni-Al alloys will allow to find the methods to control the producing of materials with desired properties. Practical implications: Using of hydrogen treatment is effective to produce Al-based alloys with improved magnetic properties. Originality/value: Treatment in hydrogen atmosphere allows improving the glass-forming ability in Hf-Ni-Al alloys.

2

Fe2+- and Er2+-intercalative modification of porous and electron structure of activated carbon and its influence on supercapacitor parameters

Venhryn B.Ya., Grygorchak I.I., Kulyk Yu.O., Mudry S.I., Strelchuk V V, Budzulyak S I, Dovbeshko G I, Fesenko O M

Materials Science Poland

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2014

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Vol. 32, No. 2

272--280

EN

An influence of both porous and electron structure on the processes in an electric double layer (EDL) determining the main working parameters of carbon-based supercapacitors has been studied in order to improve them. The investigations involved impedance spectroscopy, X-ray small angle scattering, confocal micro-Raman spectroscopy, infra-red and M¨ossbauer spectroscopy. Fe2+- and Er2+-intercallative modifications of nanoporous carbon were performed. It was found that the modification process characteristics correlated with the structure parameters of the EDL.

3

Influence of pulse laser irradiation on structure and mechanical properties of amorphous Fe73.1Nb3Cu1.0Si15.5B7.4 alloy

Mudry S.I., Nykyruy Yu.S., Kulyk Yu.O., Stotsko Z. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 1

7--11

EN

Purpose: The aim of this work was to study structure changes in Fe-based amorphous ribbon under laser radiation, determine it dependence from laser treatment parameters and establish the correlation between structure and microhardness. Design/methodology/approach: Amorphous ribbons of Fe73.1Nb3Cu1.0Si15.5B7.4 alloy, obtained by rapid cooling from the melt, has been treated by pulsed laser radiation with wavelength λ = 1.06 μm and pulse duration τ = 130 ns. Structure transformation has been studied by means of X-ray diffraction method, which allowed us to determine the phase composition, volume fraction and grain size of crystalline phases has been determined. Findings: It has been shown, that laser treatment method allows forming an amorphous-nanocrystalline composite. It was found that microhardness of ribbon increases after irradiation and linearly depends on percent of crystalline phase. Practical implications: Laser treatment can be used as an substitute of isothermal heat treatment to produce amorphous-nanocrystalline materials with improved properties. Originality/value: The originality of this work is based on applying of pulse laser irradiation for modifying structure of amorphous Fe73.1Nb3Cu1.0Si15.5B7.4 alloy.

4

Effect of ultrasonic treatment of activated carbon on capacitive and pseudocapacitive energy storage in electrochemical supercapacitors

Venhryn B. Y., Grygorchak I.I., Stotsko Z. A., Bakhmatyuk B.P., Mudry S.I., Kulyk Yu.O.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 60, nr 2

59--65

EN

Purpose: Use of ultrasonic radiation for improving the properties of activated carbon was the aim of this paper. Increase of density of states at Fermi level was the main factor, responsible for working characteristics of electrochemical supercapacitors. Design/methodology/approach: Working parameters of supercapacitors on the base of activated carbon have been studied by means of precisional porometry, small angle X-ray scattering, cyclic voltamerometry, electrochemical impedance spectroscopy and computer simulation methods. Findings: The possibility to effect the interface between activated carbon and electrolyte by means of ultrasonic treatment in cavitation and noncavitation regimes is proved. It is shown that ultrasonic treatment in noncavitation regimes causes the significant increase of density of states at Fermi level that results in better farad-volt dependences. Research limitations/implications: This research is a complete and accomplished work. Practical implications: Modification of electric double layer by meanans in ultrasonic treatment, proposed in this work, could be regarded as effective way to obtaine the advanced electrode materials in devices of energy generation and storage. Originality/value: This work is important for physics, material science and chemistry because it is related with new possibilities to change the mobility of charge carries in electric double layer by means of ultrasonic irradiation.

5

Porous structure of carbon-based materials studied by means of X-ray small angle scattering method

Venhryn B.Ya., Grygorchak I.I., Kulyk Yu.O., Mudry S.I., Shvets R.Ya.

Optica Applicata

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2008

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Vol. 38, nr 1

119-125

EN

The porous structure of carbon-graphite materials: styrene-divinylbenzene copolymer (SBC) and fruit stones (FS) has been studied by means of X-ray small angle scattering method. The angular dependences of scattered intensities have been obtained and analyzed by means of the Guinier method. The main parameters of porous structure have been determined (inertia radius, pore size distribution functions, specific surface areas).