Andrey Mikhaylov

Mr. Andrey Mikhaylov

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2017 in Progress in Natural Science: Materials International
Verified
Journal Article
Open access
Roman S. LaptevRoman S. Laptev
Roman S. Laptev
Viktor KudiiarovViktor Kudiiarov
Viktor Kudiiarov
YBYuri S. Bordulev
Yuri S. Bordulev
AMAndrey Mikhaylov
Andrey Mikhaylov
ALAndrey M. Lider
Andrey M. Lider
Titanium and its alloys are promising materials for hydrogen storage. However, hydrogen penetration accompanies the exploitation of hydrogen storage alloys. In particular, hydrogen penetration and accumulation in titanium alloys changes their mechanical properties. Therefore, the research works of such materials are mainly focused on improving the reversibility of hydrogen absorption-liberation processes, increasing the thermodynamic characteristics of the alloys, and augmenting their hydrogen storage capacity. In the process of hydrogenation-dehydrogenation, the formed defects both significantly reduce hydrogen storage capacity and can also be used to create effective traps for hydrogen. Therefore, the investigation of hydrogen interaction with structural defects in titanium and its alloys is very important. The present work, the hydrogen-induced formation of defects in the alloys of commercially pure titanium under temperature gas-phase hydrogenation (873 K) has studied by positron lifetime spectroscopy and Doppler broadening spectroscopy. Based on the evolution of positron annihilation parameters τf, τd, their corresponding intensities If, Id and relative changes of parameters S/S0 and W/W0, the peculiarities of hydrogen interaction with titanium lattice defects were investigated in a wide range of hydrogen concentrations from 0.8at% to 32.0at%

22 April 2020 in Journal of Synchrotron Radiation
Verified
Journal Article
Open access
AMAndrey Mikhaylov
Andrey Mikhaylov
SRStefan Reich
Stefan Reich
MZMargarita Zakharova
Margarita Zakharova
VVVitor Vlnieska
Vitor Vlnieska
Roman S. LaptevRoman S. Laptev
Roman S. Laptev
DKDanays Kunka
Danays Kunka
Different approaches of 2D lens arrays as Shack–Hartmann sensors for hard X-rays are compared. For the first time, a combination of Shack–Hartmann sensors for hard X-rays (SHSX) with a super-resolution imaging approach to perform multi-contrast imaging is demonstrated. A diamond lens is employed as a well known test object. The interleaving approach has great potential to overcome the 2D lens array limitation given by the two-photon polymerization lithography. Finally, the radiation damage induced by continuous exposure of an SHSX prototype with a white beam was studied showing a good performance of several hours. The shape modification and influence in the final image quality are presented.

6 September 2019 in Polymers
Verified
Journal Article
Open access
PDF file
VVVitor Vlnieska
Vitor Vlnieska
AMAndrey Mikhaylov
Andrey Mikhaylov
MZMargarita Zakharova
Margarita Zakharova
Eva BlascoEva Blasco
Eva Blasco
DKDanays Kunka
Danays Kunka
One of the types of negative tone photoresists is composed of at least a catalyst, a solvent, and epoxy resin. This is the primary raw material for lithography technology. To ensure high-quality pattern transfer in the lithography process, it is crucial to control the properties of the photoresist. In this work, a set of resins based on Bisphenol-A were synthesized. The obtained resins have been characterized regarding the chain size and its derivative products. As a second step, an epoxidation reaction was performed and the epoxy groups were quantified. The profile of the resins, obtained by mass spectroscopy (ESI-µ-TOF-MS), showed that it is possible to tune the chain sizes of the polymers and their derivate by controlling the parameters of the polymerization reaction. Three profiles of resins were achieved in this study. Nuclear magnetic resonance (NMR) indicates an epoxidation in the range of 96%, when comparing the phenolic peak intensity before and after the reaction. Differential Scan Calorimetry (DSC) measurements confirmed the different oligomer profiles of resins, showing different glass transition temperatures.

26 April 2019 in Optics Letters
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Journal Article
Closed access
PDF file
MZMargarita Zakharova
Margarita Zakharova
SRStefan Reich
Stefan Reich
AMAndrey Mikhaylov
Andrey Mikhaylov
VVVitor Vlnieska
Vitor Vlnieska
TRTomy Dos Santos Rolo
Tomy Dos Santos Rolo
DKDanays Kunka
Danays Kunka
In this Letter, we present the application of the inverted Hartmann mask for time-resolved single-shot phase-contrast x-ray imaging. The inverted Hartmann mask is a periodic array of free-standing gold pillars. The array is manufactured by UV lithography and electroplating. Time-resolved measurements are performed for imaging of pulsed laser ablation in liquids using white-beam synchrotron radiation. The inverted Hartmann mask in combination with a single-shot imaging technique provides sufficient differential phase contrast even at very short exposure times. It can be effectively used for phase-contrast x-ray imaging of fast dynamic processes with temporal resolution on the millisecond scale.

22 May 2018 in Metals
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Journal Article
Open access
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TPTatyana S. Priamushko
Tatyana S. Priamushko
AMAndrey Mikhaylov
Andrey Mikhaylov
MBMariia Babikhina
Mariia Babikhina
Viktor KudiiarovViktor Kudiiarov
Viktor Kudiiarov
Roman S. LaptevRoman S. Laptev
Roman S. Laptev
Currently, standard samples of hydrogen-metal systems meeting the requirements of glow discharge optical emission spectrometers (GD-OES) are not available on the market. This article describes the preparation of Zr-Nb-H standard samples and the calibration of GD-OES with the usage of these samples. Samples of Zr-2.5Nb were chosen as the material for sample production. The creation procedure includes five main steps: sample preparation (polishing to an average roughness, Ra, of 0.04 m using sandpaper), annealing, hydrogenation, maintenance in an inert gas atmosphere, and characterization of the samples. The absolute hydrogen concentration in the samples was determined volumetrically and calculated from the weight change. The distribution of hydrogen was studied using GD-OES Profiler 2 by Jobin Yvon Emission Horiba Group. As a result of this work, calibration curves of Zr, H, Nb, O, and other elements were obtained. The calibration errors were in the range of 1–5%.

23 October 2021 in Journal of Imaging
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Journal Article
Open access
PDF file
MZMargarita Zakharova
Margarita Zakharova
AMAndrey Mikhaylov
Andrey Mikhaylov
VVVitor Vlnieska
Vitor Vlnieska
DKDanays Kunka
Danays Kunka
We present the application of single-shot multicontrast X-ray imaging with an inverted Hartmann mask to the time-resolved in situ visualization of chemical reaction products. The real-time monitoring of an illustrative chemical reaction indicated the formation of the precipitate by the absorption, differential phase, and scattering contrast images obtained from a single projection. Through these contrast channels, the formation of the precipitate along the mixing line of the reagents, the border between the solid and the solution, and the presence of the scattering structures of 100–200 nm sizes were observed. The measurements were performed in a flexible and robust setup, which can be tailored to various imaging applications at different time scales.