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Документ Structure and phase formation features of Ti-Zr-Ni quasicrystalline films under heating(Sumy State University, 2019) Malykhin, S. V.; Kondratenko, V. V.; Kopylets, I. A. ; Surovitskiy, S. V.; Baturin, A. A.; Mikhailov, I. F.; Reshetnyak, M. V.; Borisova, S. S.; Bogdanov, Yu. S.The paper describes the growth features of thin Ti-Zr-Ni films prepared by the method of magnetron sputtering of the targets with compositions Ti₅₃Zr₃₀Ni₁₈ and Ti₄₁Zr₃₈.₃Ni₂₀.₇ on the substrates at 300 K with subsequent annealing in vacuum. The formation peculiarities of phase composition, structure and thermal stability of quasicrystalline thin films were studied. It was established that in initial state the films were X-ray-amorphous or nanocrystalline with coherence lengths (according to Scherrer) near 1.6-1.8 nm independently on the element composition of the sputtered target. This structure is relatively stable up to the temperature 673 K when the formation of the quasi-crystalline phase begins. In the films with composition of Ti₅₃Zr₃₀Ni₁₈. It is added with an admixture of the 1/1 W-crystal approximant phase. In the films with Ti₄₁Zr₃₈.₃Ni₂₀.₇ composition, an optimal annealing temperature is between 823 K and 873 K. Additionally, for the first time, the data on the formation of 2/1 approximant crystal as an admixture phase in this system were obtained. Under annealing at the temperatures higher than 873 K, the decomposition of the quasi-crystalline and approximant phases into crystalline phases stable at higher temperatures according to the equilibrium phase diagram was established.Документ Features of the initial stage of the formation of Ti-Zr-Ni quasicrystalline thin films(Sumy State University, 2020) Malykhin, S. V.; Kondratenko, V. V.; Kopylets, I. A. ; Surovitskiy, S. V.; Shipkova, I. G.; Mikhailov, I. F.; Zubarev, Evgeniy N.; Bogdanov, Yu. S.Using the methods of X-ray diffraction, transmission and scanning microscopy, the features of the initial stage of the formation of the quasicrystalline phase in thin films of Ti-Zr-Ni are studied. The films were obtained by magnetron sputtering of a target of the composition Ti₄₁Zr₃₈.₃Ni₂₀,₇ (at. %) with deposition on substrates at T = 300 K and further vacuum annealing. It was established that immediately after deposition, the films are X-ray amorphous, nanostructured. An analysis of the radial distribution functions shows that immediately after deposition, the structural state of a disordered cluster, which is topologically close to icosahedral, prevails in the near atomic medium. It is concluded that the atoms are not arranged randomly, but form a "transitional" structure with an imperfect order like three shells of the Bergman cluster stacking using icosahedrons and dodecahedrons. Such a structure is a "prepared" nucleus for the further formation of the icosahedral phase upon heating. An analysis of the annealing results suggests that the qualitative nature of the transition from the pseudo-amorphous to the quasicrystalline phase and the scale of the transformations are determined by the annealing time and temperature, as well as by the film thickness. The smaller the thickness, the more the annealing processes are inhibited. It was shown that by annealing the films of a thickness of 6 μm or more at 500 °C for more than 28 h, single-phase quasicrystalline coatings with a quasicrystallinity parameter aq of about 0.5245 nm can be obtained.Документ Structural-phase changes in thin films and surface layers of Ti₄₁.₅Zr₄₁.₅Ni₁₇ alloy, stimulated by radiation-thermal impact of hydrogen plasma(Kharkiv Institute of Physics and Technology, 2019) Malykhin, S. V.; Makhlai, V. A.; Surovitskiy, S. V.; Borisova, S. S.; Herashchenko, S. S.; Kondratenko, V. V.; Kopylets, I. A.; Baturin, A. A.; Terentyev, D.X-ray diffraction and SEM microscopy were used to study structural and phase changes in the surface layers of a Ti₄₁.₅Zr₄₁.₅Ni₁₇ alloy bulk sample (target) and a thin film (deposited by magnetron sputtering of the target) under radiation-thermal action of pulsed hydrogen plasma with a thermal load of 0.6 MJ/m² in QSPA Kh-50 installation. It is established that the irradiation results in the formation of a two-phase state: the icosahedral quasicrystalline phase together with the phase of the 1/1 approximant crystal (W-phase). As a result of isothermal (550°C) annealing, the content of the quasicrystalline phase increases.