The influence of annealing temperature and annealing time on the structure of coatings with the composition of Ti41Zr41Ni18 (at.%) was analyzed. The conditions for obtaining nanodispersed, single-phase quasicrystalline and 2/1 phase-approximant coatings have been determined. Detailed data about the structure of the films of the little-studied 2/1 approximant phase were collected, using XRD and high-resolution transmission electron microscopy. By nanoindentation, a comparative study of mechanical properties was carried out with samples having different phase compositions. It was established that single-phase coatings of the 2/1 approximant phase are superior to quasi-crystalline ones in terms of hardness and Young's modulus. Coatings of the 2/1 approximant phase reach a hardness of H = 15.42 GPa, Young's modulus of E = 201 GPa at the ratio H/E = 0.077. This allows them to be considered as close to ultra-strong materials.

This paper presents the results of fabricating a model sample of a multilayer coating on a Al2O3 substrate, which consisted of 30 periods of alternately deposited 10.5-nm-thick layers of Ti41Zr41Ni18 and 2.5-nm-thick layers of W. The effect of annealing for 1 h at 500, 600, and 700 °C was studied. Characterization of the phase and structural state of the coating by X-ray diffractometry and small-angle X-ray reflectometry was carried out. It was found that during the annealing process, the tungsten layers in the multilayer composition did not undergo significant changes, and all alterations occur only in the Ti41Zr41Ni18 layers. Annealing affected the thickness of the layers, density, and interlayer roughness. It has been experimentally shown that the phase transformation ”quasicrystal → 2/1 crystalline approximant” is accompanied by an 8.3% volume increase compared to the volume of the quasicrystalline phase, but this does not lead to the destruction of the periodic composition. The multilayer structure proved to be resistant to high temperatures and, despite phase changes, did not lose its bond with the substrate. The used combination of materials and the high annealing temperature did not generate significant internal stresses or mechanical damage. The results obtained in this study allow for the further controlled formation of layered quasicrystal/tungsten microsystems of various designs with different layer thicknesses. The next perspective involves conducting practical tests with plasma to study the radiation-thermal impact.

By the method of X-ray tensometry (=0.154 nm), the dependences of residual stresses in Mo/Si multilayer Xray mirrors (MXMs) obtained by direct-current magnetron sputtering were studied as a function of the sputtering Ar pressure in the range of 1…4 mTorr. It is shown that an increase in pressure is accompanied by an increase in stresses from ~ 0.4 to ~ 0.8 GPa for a group of mirrors with periods near 7 nm and from ~ 0.9 to ~ 1.6 GPa for a group of mirrors with periods near 14 nm. The angles of texture misorientation for Mo crystallites were measured as a function of argon pressure. Mechanisms have been proposed to explain the reasons for the increase in stresses.

The temperature dependence of the electrical resistivity in the temperature range from 4.4 to 300 K for Ti41Zr41Ni18 (at. %) thin coatings of different crystal perfection and phase composition was studied. The coatings were deposited by magnetron sputtering with subsequent vacuum annealing in various modes ensuring the formation of several heterophase combinations, which included 1/1 and 2/1 approximation phases, a quasicrystalline icosahedral phase, a Laves phase (Ti, Zr)2Ni, and an α-Ti (Zr) solid solution. The structure before and after annealing was studied by X-ray diffractometry. It was established that coatings with a predominant content of amorphous, quasicrystalline, or approximant 2/1 phases have a temperature coefficient of resistance less than zero, while samples with a predominance of crystalline phases demonstrate characteristic metallic conductivity. The temperature dependence of the electrical resistivity of the Ti41Zr41Ni18 quasicrystalline coating turned out to be similar to the dependence in bulk samples of the Ti40Zr40Ni20 composition. The electrical resistivity of the approximant 2/1 phase with a low content of the additional Laves phase in the film has an almost constant value in the entire investigated temperature range.

The temperature dependence of electrical resistivity in the temperature range from 4.4 to 300 K for Ti41Zr41Ni18 (at.%) thin coatings of various crystal perfection and phase compositions has been investigated. The films were deposited by the magnetron sputtering method. The following vacuum annealing in various modes provided several combinations of the film phases such as 1/1 and 2/1 crystal-approximant phases, the quasicrystalline icosahedral phase, Laves (Ti,Zr)2Ni phase and & alpha;-Ti(Zr) solid solution phase. The structure and composition of the films before and after annealing were studied in detail by X-ray diffractometry and cross-sectional high-resolution transmission electron microscopy. Samples with predominant amorphous, quasi-crystalline, and approximant 2/1 phases have a temperature coefficient of resistance less than zero, while samples dominated by crystalline phases exhibit the characteristic metallic conductivity. For the quasicrystalline Ti41Zr41Ni18 film, the temperature dependence of the electrical resistance turned out to be similar to that of bulk samples with the composition Ti40Zr40Ni20. A significant effect of the presence of phases with metallic conduction on the overall conductivity of the coating is described. The electrical resistance of the 2/1 approximant phase with a low content of the additional Laves phase in the film has an almost constant value over the entire temperature range under study.

The work deals with the issue of miniaturization of template images using X-ray radiation. The compression method is based on the fact that X-ray radiation is directed at a specific template that reflects X-ray radiation at an grazing angle and a one-dimensional compressed image is recorded on a plane not parallel to the plane of the template. The advantage of this method of image compression is the relative simplicity of its implementation. The paper proposes the use of X-ray multilayer mirrors as reflective X-ray masks (RXM) for one-dimensional image compression. Control of the structural parameters of multilayer mirrors was carried out on a DRON- 3M X-ray diffractometer. The RXM template was formed by sputtering an absorbing WC layer with a thickness of ~0.2 μm through a certain stencil on the surface of a multilayer mirror. The test of the RXM with mirrors based on a pair of WC/Si materials in synchrotron radiation (l~3.5 nm) was carried out. A 14-fold compression of the reflective segments of the RXM with a size of ~50 μm was obtained. Theoretically, the principle possibility of obtaining compression of reflective segments to submicron sizes is shown.

The effect of annealing temperature on the structure and mechanical properties of Ti41Zr39Ni20 coatings was examined. Coatings were deposited on stainless-steel substrates via magnetron sputtering and then annealed in a vacuum under temperatures from 200 to 850 degrees C. Evaluation of structure and mechanical properties under annealing was performed using cross-sectional transmission electron microscopy, X-ray diffraction analysis, and ultra-nano indentation. Further, mechanical durability was assessed by reciprocating sliding tests. The relationships between the mechanical properties and structural-phase characteristics of the coatings were established. Results suggested that the mechanical properties of the 2/1 approximant phase were better than those of the quasicrystal phase, probably due to the peculiarity of the atomic-crystal structure of the 2/1 approximant phase. In addition, the formation of layered structure caused by non-uniform phase transitions was observed for coatings annealed at 600 degrees C. The nanocrystalline structure of the top layer and high concentration of the 2/1 approximant phase resulted in the highest values of hardness (25 GPa) and hardness/elasticity ratio (0.14).

Structural and phase changes in thin films obtained by magnetron sputtering of a target with the composition Ti41Zr38.3Ni20.7 (at.%) were studied under isothermal vacuum annealing in the temperature range from 400 to 800 C. The boundaries of the thermal stability of the phases have been determined. Coatings consisting of a single icosahedral quasicrystalline phase, as well as films consisting of the 2/1 crystal-approximant phase were obtained. The features of the phase transformation of a quasicrystal into an approximant crystal were investigated, and the activation energy of this transformation was determined at a level of 94 kJ/mol. The dependence of the degree of phase transformation on the temperature and duration of annealing has been established.

The properties of Ti41Zr38.3Ni20.7 thin films under radiation-thermal action of hydrogen plasma with a surface heat load of 0.2 MJ/m2 was studied at the QSPA Kh-50 quasi-stationary plasma accelerator (NSC KIPT).The phase composition, structural state, and surface morphology were studied using X-ray diffraction and scanning electron microscopy. It was found that the quasicrystalline phase and related crystalline phases, the Laves phase, the α-solid solution, and the 2/1 phase of the Ti-Zr-Ni approximant crystal were stable under irradiation with up to 20 hydrogen plasma pulses. The phase composition did not change. It is shown that the changes in the coatings mainly manifest themselves as changes in the substructure of the observed phases. With an increase in the plasma exposure dose, the structure of the quasicrystalline icosahedral phase improves, and the size of the coherence regions increases. In the films consisting of crystalline phases, a partial phase transformation is observed with a redistribution of components between the 2/1 phase of the approximant crystal and the α-solid solution phase. It was found that thin films of the TiZr-Ni system containing a quasicrystalline icosahedral phase, irradiated with radiation-thermal plasma pulses, are less prone to cracking than coatings with crystalline phases of the same system.

The strong influence of the orientation of an external magnetic field of a system of permanent magnets on the crystal structure of cobalt films grown on an amorphous carbon sublayer was revealed by the methods of transmission electron microscopy and selected area diffraction. While the horizontal component of the magnetic field strength impedes the process of cobalt grains growth, the vertical one, on the contrary, contributes to this process. The vertical component of the magnetic field promotes strong growth of crystalline cobalt grains with an axis [0001] perpendicular to the film surface at the expense of grains with different orientations. As the strength of the vertical component of the magnetic field increases to H approximate to 1.2 x 104 Oe, the size of some crystalline grains with orientation [0001] reaches about 1 mu m in the cobalt film with a nominal thickness of 8 nm. In a horizontal magnetic field of the order of 1.2 x 104 Oe, the average grain size is only 16 nm, which is only twice the nominal film thickness. The paper discusses issues related to the influence of magnetic crystallographic anisotropy and external magnetic field on the processes of nucleation during structure rearrangement.

The synthesis and structural analysis of Mo/B periodical multilayer X-ray mirrors (PMMs) for beyond extreme ultraviolet (BEUV) optics was performed. The PMMs were deposited by a combination of pulsed DC and radio frequency (RF) magnetron sputtering. The structure was analyzed by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and grazing incidence X-ray reflectometry. The formation of 0.35 nm-thick interlayers comprised of a mixture of molybdenum borides was observed at the Mo/B interfaces. Furthermore, a low interface roughness of 0.3–0.4 nm was reported. The temperature of the substrate increased due to the increase in the sputtering power. This resulted in an increase in the thickness of the interlayers and the interface roughness; subsequently, the optical properties of the PMM deteriorated. Theoretical calculations were performed based on the real structure of the PMM to predict the reflectivity at a working wavelength of 6.7 nm. The reflectivity of approximately 53% was two times higher than that of the conventional B4C-based BEUV mirrors. Based on our study results, it can be concluded that the as-synthesized PMMs will perform better than the traditional mirrors and can be effectively used for the development of the next generation of BEUV lithography.

The principal possibility of manufacturing Si/Mg2Si multilayers by alternately deposited Si and Mg layers is demonstrated. The study of such Si/Mg2Si multilayer structure in the initial state and after thermal annealing in a temperature range of 100-300 degrees C was made by X-ray diffraction methods. It was shown that a low level of the interface roughness (similar to 0.8 nm) can be achieved in the Si/Mg2Si multilayer manufactured by the proposed method. Such Si/Mg2Si multilayers are stable up to 300 degrees C.

X-ray diffraction and SEM microscopy were used to study the structural and phase changes in a thin film obtained by magnetron sputtering of a Ti52Zr30Ni18 target (at.%) on a steel substrate under the radiation-thermal influence of pulsed hydrogen plasma on an QSPA Kh-50 accelerator. A technique has been worked out for the formation of the quasicrystalline and crystal-approximant phases as a result of high-speed quenching using pulsed action with a heat load of 0.6 MJ/m2. The changes in the contents of these phases as well as in their structure and substructure parameters were studied during isothermal vacuum annealing at a temperature of 550 °C and also as a result of irradiation with 5 plasma pulses in the range of heat load from 0.1 to 0.4 MJ/m2. The quasicrystalline phase was found to be resistant to irradiation with hydrogen plasma.

Исследован механизм взрывной кристаллизации аморфных плёнок кобальта, выращенных на аморфном углероде в отсутствии и при наличии сильного неоднородного магнитного поля.Установлено, что ключевым фактором для реализации взрывной кристаллизации является углерод, поступающий в плёнку кобальта из работающего С-магнетрона во время осаждения слоя кобальта.Легирование растущей плёнки кобальта

The structure of Mo/B periodical multilayer coatings for beyond extreme ultraviolet (BEUV) optics was investigated. The coatings were deposited by a combination of Pulse DC/RF magnetron sputtering and investigated by HRTEM, XPS, and grazing incidence X-ray reflectometry. It was shown that the formation of thin interlayers occurred at Mo/B interfaces. The thickness of interlayers was around 0.4 nm, and they consisted of a mixture of molybdenum borides. A low interface roughness of 0.3-0.4 nm was reported. Theoretical calculation based on the real structure predicted two times higher reflectivity at the wavelength of 6.7 nm compared with conventional BEUV mirrors based on B4C.

This review paper summarizes and provides an overview of our recent studies related to two types of short-period multilayer X-ray mirrors, W/B4C and Co/C. It deals with the experimental observation of the layer intermixing effects and how they affect the X-ray mirror's optical performance. The paper presents also some examples of using the fabricated X-ray mirrors in focusing and imaging experiments at the working wavelengths 2.48 nm and 4.47 nm.

Properties of CrB2 thin diffusion layers sputtered in Mo/Si multilayer structures and their effect on the x-ray/EUV reflectance are reported. A special attention is paid to determine a critical thickness t* for barrier layers where they isolate parent layers of Mo and Si completely and to reveal the degree of interaction of the barrier material with parent materials. A dependence of t* on the deposition rate of CrB2 is found. CrSi2 and B3Si are established as the most probable phases formed in the barrier layers. The diffusion coefficients and temperature during formation of CrB2 are estimated. The use of thin CrB2 barriers is shown to be profitable in a fabrication of the EUV mirrors with enhanced reflectivity.

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, the largest quantity of the quasicrystalline phase with a characteristic parameter aq  0.517 nm is observed at the annealing temperature of 673 K. 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. The quasicrystalline phase is characterized by the quasicrystallinity parameter aq  0.5205 nm. 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.