Partner: Uliana Yakhnevych

Lviv Polytechnic National University (UA)

Recent publications
1.Syvorotka I.I., Sugak D., Yakhnevych U., Buryy O., Włodarczyk D., Pieniążek A., Zhydachevskyy Y., Levintant-Zayonts N., Savytskyy H., Bonchyk O., Ubizskii S., Suchocki A., Investigation of the interface of Y3Fe5O12/Gd3Ga5O12 structure obtained by the liquid phase epitaxy, Crystal Research and Technology, ISSN: 1521-4079, DOI: 10.1002/crat.202100180, No.2100180, pp.1-10, 2022
Abstract:

The changes in the optical, structural, mechanical properties, and chemical composition of Y3Fe5O12/Gd3Ga5O12 (YIG/GGG) single crystal structures grown by liquid phase epitaxy, particularly at the interface between the film (Y3Fe5O12) and the substrate (Gd3Ga5O12), are studied. Different complementary techniques, including optical microscopy, local spectrophotometry, electron probe microanalysis, micro-Raman spectroscopy, and nanohardness analysis are used. The main finding of the study is an experimental approach, in which the probe of the measuring device (light beam, electron beam, nanoindenter) is directed to the surface of the studied sample in a direction perpendicular to the direction of structure growth, and the surface is scanned along this direction. It allows to obtain the profiles of changes in refractive properties, nanohardness, optical absorption, chemical composition, and intensity of phonon spectrum bands at the transition from the GGG to YIG. It is established that the lengths of the scanning intervals, at which the changes of various properties of a specimen occur, differ significantly. The obtained results are affected by the size of the probes and by the sensitivities of both the particular measuring method and the particular physical property of the material to changes in the chemical composition and crystalline structure of the sample.

Keywords:

electron probe microanalysis, gadolinium gallium garnet, interface, nanohardness, Raman scattering, spectrophotometry, yttrium iron garnet

Affiliations:
Syvorotka I.I.-Scientific Research Company Carat Ukraina (UA)
Sugak D.-Lviv Polytechnic National University (UA)
Yakhnevych U.-Lviv Polytechnic National University (UA)
Buryy O.-Lviv Polytechnic National University (UA)
Włodarczyk D.-Institute of Physics, Polish Academy of Sciences (PL)
Pieniążek A.-Institute of Physics, Polish Academy of Sciences (PL)
Zhydachevskyy Y.-Institute of Physics, Polish Academy of Sciences (PL)
Levintant-Zayonts N.-IPPT PAN
Savytskyy H.-Ya.S. Pidstryhach Institute for Applied Problems of Mechanics and Mathematics NASU (UA)
Bonchyk O.-Ya.S. Pidstryhach Institute for Applied Problems of Mechanics and Mathematics NASU (UA)
Ubizskii S.-Lviv Polytechnic National University (UA)
Suchocki A.-Institute of Physics, Polish Academy of Sciences (PL)
2.Sugak D., Syvorotka I., Yakhnevych U., Buryy O., Levintant-Zayonts N., Savytskyy H., Bonchyk O., Ubizskii S., Comparative investigations of nanohardness and impurity distribution profiles of lithium niobate single crystals diffusion doped by copper ions, Crystal Research and Technology, ISSN: 1521-4079, DOI: 10.1002/crat.201900117, Vol.54, No.12, pp.1900117-1-7, 2019
Abstract:

Spatial changes of optical and mechanical properties of doped lithium niobate (LN, LiNbO3) single crystals are investigated. The crystals are doped with copper ions by thermal diffusion at elevated temperatures. LiNbO3 crystal absorption spectra are recorded in a direction perpendicular to the direction of diffusion. The concentrations of copper ions are calculated using the Smakula–Dexter formula. To determine a relation between changes of optical and mechanical properties, the hardness profiles of the doped crystals are investigated by the nanoindentation technique. Young's modulus and hardness are specified in accordance with the Oliver–Pharr method.

Affiliations:
Sugak D.-Lviv Polytechnic National University (UA)
Syvorotka I.-Scientific Research Company Carat Ukraina (UA)
Yakhnevych U.-Lviv Polytechnic National University (UA)
Buryy O.-Lviv Polytechnic National University (UA)
Levintant-Zayonts N.-IPPT PAN
Savytskyy H.-Ya.S. Pidstryhach Institute for Applied Problems of Mechanics and Mathematics NASU (UA)
Bonchyk O.-Ya.S. Pidstryhach Institute for Applied Problems of Mechanics and Mathematics NASU (UA)
Ubizskii S.-Lviv Polytechnic National University (UA)