rus
Issue #6/2025
A. V. Orlova, L. O. Tcelykh, D. S. Koshelev, A. V. Bulatov, M. R. Garbuzova, K. R. Zezyulya, E. D. Marshev, L. S. Rubanova, T. L. Tsymbal, V. V. Utochnikova
Bimetallic Terbium and Europium Tetrafluoroterephthalates with Phenanthroline: Photostability and
Bimetallic Terbium and Europium Tetrafluoroterephthalates with Phenanthroline: Photostability and
DOI: 10.22184/1993-7296.FRos.2025.19.6.500.507
The luminescent complexes of terbium and europium with tetrafluoroterephthalic acid and phenanthroline were studied for application in thermometry. It was shown that in contrast to a mixture of individual complexes demonstrating various photodegradation rates, the bimetallic complex retains a stable intensity ratio of the Tb3+ and Eu3+ emission bandswith a general decrease in the luminescence intensity. The composite materials based on the synthesized complexes in polyimide and polystyrene matrices were developed with simultaneous combination of thermosensitive properties with mechanical stability. The results obtained offer opportunities for the development of stable luminescent thermometers for biological and microelectronic applications.
The luminescent complexes of terbium and europium with tetrafluoroterephthalic acid and phenanthroline were studied for application in thermometry. It was shown that in contrast to a mixture of individual complexes demonstrating various photodegradation rates, the bimetallic complex retains a stable intensity ratio of the Tb3+ and Eu3+ emission bandswith a general decrease in the luminescence intensity. The composite materials based on the synthesized complexes in polyimide and polystyrene matrices were developed with simultaneous combination of thermosensitive properties with mechanical stability. The results obtained offer opportunities for the development of stable luminescent thermometers for biological and microelectronic applications.
Теги: bimetallic complexes luminescent thermometry photodegradation polymer composites. биметаллические комплексы комплексы лантанидов люминесцентная термометрия полимерные композиты. lanthanide complexes фотодеградация
Bimetallic Terbium and Europium Tetrafluoroterephthalates with Phenanthroline: Photostability and Application in Thermometry
A. V. Orlova 1, L. O. Tcelykh 1, D. S. Koshelev 1, A. V. Bulatov 2, M. R. Garbuzova 2, K. R. Zezyulya 2, E. D. Marshev 2, L. S. Rubanova 2, T. L. Tsymbal 2, V. V. Utochnikova 1
Lomonosov Moscow State University, Moscow, Russia
Sirius Educational Center, Krasnodar region, Sirius Federal Territory, Russia
The luminescent complexes of terbium and europium with tetrafluoroterephthalic acid and phenanthroline were studied for application in thermometry. It was shown that in contrast to a mixture of individual complexes demonstrating various photodegradation rates, the bimetallic complex retains a stable intensity ratio of the Tb3+ and Eu3+ emission bandswith a general decrease in the luminescence intensity. The composite materials based on the synthesized complexes in polyimide and polystyrene matrices were developed with simultaneous combination of thermosensitive properties with mechanical stability. The results obtained offer opportunities for the development of stable luminescent thermometers for biological and microelectronic applications.
Key words: lanthanide complexes, luminescent thermometry, photodegradation, bimetallic complexes, polymer composites.
Article received: 14.07. 2025
Article accepted: 09.09. 2025
Photostability study
of bimetallic terbium
and europium tetrafluoroterephthalates with phenanthroline
for application in thermometry
The luminescent thermometers based on lanthanide (Ln) complexes are of considerable interest for various fields of application requiring accurate temperature control, due to their high sensitivity, spatial resolution, and possible contactless and remote measurement of characteristics [1–13]. In microelectronics and nanoelectronics, these materials are indispensable for real-time monitoring local overheating in the “hot spots” of integrated circuits, processors, power semiconductor devices, and light-emitting diodes. Thin (50–100 μm), transparent, and flexible polymer films with a sensor can be deposited directly to the studied surfaces of chips or heat sinks, while providing high spatial resolution (determined by the optical detection system), non-invasiveness, resistance to electromagnetic interference, and operation in the range of 25–100 °C and higher. In the field of biomedical research and diagnostics, the nanoparticles of complexes or thin sensor layers open up space for measuring intracellular temperature or temperature near the biological samples under a microscope. This is facilitated by the component biocompatibility, possible excitation in the near UV range (365–405 nm) and bioimaging capabilities. For aviation and space technology, the composite films based on polymers and luminescent complexes offer a solution for thermal monitoring of structural elements on the surface or inside the composites under the extreme conditions of vibration, vacuum or aggressive environments. In this case, the key advantages include the composite mechanical strength and flexibility, its high thermal resistance and photostability, as well as chemical inertness. In the optical materials science and non-destructive testing, such developments allow mapping the temperature fields by developing the thermosensitive coatings or incorporating sensor particles into the transparent polymers. Such activity visualizes the temperature distribution in the optical elements, microfluidic chips or in the case of local laser heating by using the optical matrix transparency, high sensitivity (up to 2.50%/°C) and fast response.
The transition to bimetallic phosphors overcomes the main constraint of luminescent thermometry, namely the time-dependent signal instability. It leads to the basis for a new sensor generation, when the requirements for long-term reliability are comparable with the need for accuracy, especially under conditions of continuous optical monitoring or aggressive environments. Among all luminescent compounds of lanthanides, special attention is paid to the soluble and stable coordination compounds (CCs) of terbium (Tb3+) and europium (Eu3+) that demonstrate intense narrow-band luminescence in the visible range [1, 14–19].
Despite the higher sensitivity in the case of mixtures of monometallic Tb3+ and Eu3+ CCs, one of the key issues in their use is different photostability, leading to a change in the intensity ratio of their emission bands over time and, as a consequence, to the temperature signal distortion [17, 19–21]. In this regard, a promising area seems to be the development of bimetallic complexes in which both lanthanide ions are located in a single structure that can ensure synchronous degradation of their luminescent centers and signal stability [1–2, 7–9, 20]. In addition, for the practical application of luminescent sensors, their integration into the polymer matrices is important, since it ensures mechanical stability, ease of processing and possible obtaining of the flexible films [7–8].
In this paper, the influence of structural factors on photostability and preservation of thermometric specifications was studied using the monometallic [Ln(TFTA)3(Phen)2] ∙ 2H2O (Ln = Tb3+, Eu3+) and bimetallic [EuxTb1‑x(TFTA)3(Phen)2] ∙ 2H2O complexes as an example. Tetrafluoroterephthalic acid (H2TFTA) and phenanthroline (Phen) were selected as the ligands, while providing efficient energy transfer to the Ln3+ ions [22–23]. Polyimide PI2050 and polystyrene were used as the polymer matrices, since they combined high optical transparency, chemical inertness and high mechanical stability.
The mono- and bimetallic complexes were synthesized using a modified method [22]. The powder XRD of the synthesized compounds (Fig. 1a) showed their complete compliance with the structural data given in the references [24]. All reflections on the diffraction patterns completely coincided with the design values for the monoclinic syngony (crystal system) (space group C2 or C2/m). The thermogravimetric analysis of [Tb2(TFTA)3(Phen)2] ∙ 2H2O (Fig. 1b) revealed a three-stage decomposition process of the complexes in accordance with the crystallization water removal (n = 2.3 ± 0.3, 85–135 °C), the elimination of phenanthroline molecules (235–340 °C) and the carboxylate fragment decomposition (407–534 °C). The scanning electron microscopy (Fig. 1c) did not find any significant differences in the particle morphology of bimetallic complexes with various Tb : Eu ratios. In both cases, the agglomerated particles with the dimensions of 50–500 nm were observed.
To obtain the polymer composites, two types of matrices were selected, namely polyimide PI2050 and polystyrene (PS). Both matrices have high thermal stability, however, polystyrene melts at the temperature of 240 °C. In addition, a solvent is required to prepare the PS-based composites that increases the preparation time of the composite material from several hours to several days depending on the product thickness, and the composite materials are more fragile and less even (Fig. 1d left). Although the composites based on PI2050 require UV irradiation for curing, they do not need any handling of solvents, can be prepared in a few tens of minutes and are thin, smooth, and flexible (Fig. 1d right).
The study of luminescent properties have determined that the luminescence spectra of monometallic complexes (Fig. 2a) demonstrate the transitions typical for the Tb3+ (5D4→7FJ, J = 6–3) and Eu3+ (5D0→7FJ, J = 0–4) ions. The intensity ratio of the main bands of Tb3+ and Eu3+ is changed smoothly with variation in the complex composition (Fig. 2a) that confirms their possible fine-tuning of luminescent characteristics. In this case, the typical transitions of the europium ion are preserved in the luminescence spectra of bimetallic complexes (Fig. 2a) even at its minimum content (0.01 at. %, or x = 0.0001). This fact indicates a high efficiency of energy transfer between the Tb3+→Eu3+ ions. Comparison of the complex spectra in powder form and in the polymer matrices demonstrated their complete correspondence.
The photostability studies (Fig. 2f–h) revealed significant differences in the behavior of monometallic complexes. At the room temperature and constant UV irradiation (λex = 365 nm, power = 15 W), the terbium complex loses 27% of the initial luminescence intensity in 200 minutes, while the europium complex loses 34%. This difference may be due to several factors: 1) various stability of coordination spheres of the Tb3+ and Eu3+ ions to the photochemical processes; 2) possible participation of the excited Tb3+ states in the photochemical reactions; 3) different efficiency of luminescence quenching by the molecular oxygen. It is noteworthy that the XRD analysis of the complexes before and after photodegradation did not reveal any changes in the crystal structure of either the terbium or europium complexes that indicated the preserved coordination sphere of the lanthanide ions and pointed to the molecular nature of degradation processes.
Furthermore, the study of bimetallic complexes even at elevated temperature (100 °C) demonstrated (Fig. 2g–h) that although the overall luminescence intensity decreases over time, the intensity ratio of terbium and europium transitions (LIR = I(690 nm)/I(545 nm)) remains practically unchanged throughout the entire observation period (40 min). This important observation confirms the prospective application of bimetallic complexes for thermometry, since their readings will not be distorted over time due to the photodegradation process.
The temperature dependences of luminescence (Fig. 2f) demonstrate the behavior typical for the lanthanide complexes: when the temperature is increased, the terbium band intensity decreases faster than that of europium that is due to various thermal quenching efficiencies of their excited states. The temperature dependence of LIR (Fig. 2g–h) is linear in the studied range (20–100 °C), and the temperature sensitivity (S = d(LIR)/dT ∙ 100%) reaches 2.50%/°C for the composite based on [(Eu0.0001Tb0.9999)2(TFTA)3Phen2] ∙ 2H2O in PI2050. It is important to note that the temperature sensitivity of LIR in the composites remains almost at the same level as for the initial complexes that confirms their promising use for the development of polymeric heat-sensitive materials.
Thus, the conducted research allowed to develop a new grade of bimetallic luminescent materials based on the coordination compounds of terbium and europium with tetrafluoroterephthalic acid and phenanthroline that has the unique properties for application in optical thermometry. The main achievement of this paper was the establishment of a fundamental difference in photostability of the mono- and bimetallic complexes: if individual Tb3+ and Eu3+ complexes demonstrate various photodegradation rates (27% and 34% in 40 minutes), then the bimetallic systems maintain a stable intensity ratio of their typical transitions even at the elevated temperatures. This effect, along with the high sensitivity of the luminescence intensity ratio to the temperature (up to 2.50%/°C) makes the developed materials promising for the precise luminescent thermometers. An important practical result was the successful integration of complexes into the polymer matrices that ensured the formation of mechanically strong, flexible and thermally stable films with the preserved functional characteristics of the complexes.
FUNDING
The works were performed with the support of the Educational Program in Practical Chemistry implemented at the Sirius Educational Center.
AUTHORS
Anastasia V. Orlova – PhD student, Faculty of the Material Science, Lomonosov Moscow State University, Moscow, Russia. E-mail: lea.rosa.17@mail.ru.
ORCID 0000-0003-2534-2835
Liubov O. Tcelykh –PhD student, Department of Chemistry Lomonosov Moscow State University, Moscow, Russia. E-mail: tcelykh@my.msu.ru.
ORCID 0000-0002-1250-4017
Daniil S. Koshelev – Cand. of Sc. (Chemistry), Junior Research Fellow, Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia, E-mail: koshelevds@my.msu.ru
ORCID 0000-0001-8210-6690
Anton V. Bulatov – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: toni.bulatov.07@mail.ru.
ORCID 0009-0005-2412-9145
Milena R. Garbuzova – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: garbuzovamilenka@gmail.com.
ORCID 0009-0007-7108-3455
Kirill R. Zezyulya – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: kirillzezyulya@gmail.com
ORCID 0009-0001-2582-479X
Evgenii D. Marshev – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: marshev07@bk.ru.
ORCID 0009-0001-6089-7695
Lada S. Rubanova – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: lada.rubanova.00@mail.ru.
ORCID 0009-0002-0425-5046
Timofei L. Tsymbal – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: cymbalt112@gmail.com.
ORCID 0009-0003-4695-4045
Valentina V. Utocnikova – Dr. of Science, Prof. Faculty of the Material Science, Lomonosov Moscow State University, Moscow, Russia. E-mail: valentina@utochnikova.ru.
ORCID 0000-0002-0830-1268
AUTHOR CONTRIBUTIONS
Anastasia Orlova: Visualization, Writing – review & editing, Project administration; Liubov Tcelykh: Visualization, Writing – original draft, Writing – review & editing; Daniil Koshelev: Writing – review & editing, Methodology, Formal analysis; Anton Bulatov: Investigation; Milena Garbuzova: Investigation; Kirill Zezyulya: Investigation; Evgenii Marshev: Investigation; Lada Rubanova: Investigation; Timofei Tsymbal: Investigation; Valentina V. Utocnikova: Writing – review & editing, Project administration, Conceptualization, Funding acquisition.
Conflicts of Interest
The authors declare no conflicts of interest.
A. V. Orlova 1, L. O. Tcelykh 1, D. S. Koshelev 1, A. V. Bulatov 2, M. R. Garbuzova 2, K. R. Zezyulya 2, E. D. Marshev 2, L. S. Rubanova 2, T. L. Tsymbal 2, V. V. Utochnikova 1
Lomonosov Moscow State University, Moscow, Russia
Sirius Educational Center, Krasnodar region, Sirius Federal Territory, Russia
The luminescent complexes of terbium and europium with tetrafluoroterephthalic acid and phenanthroline were studied for application in thermometry. It was shown that in contrast to a mixture of individual complexes demonstrating various photodegradation rates, the bimetallic complex retains a stable intensity ratio of the Tb3+ and Eu3+ emission bandswith a general decrease in the luminescence intensity. The composite materials based on the synthesized complexes in polyimide and polystyrene matrices were developed with simultaneous combination of thermosensitive properties with mechanical stability. The results obtained offer opportunities for the development of stable luminescent thermometers for biological and microelectronic applications.
Key words: lanthanide complexes, luminescent thermometry, photodegradation, bimetallic complexes, polymer composites.
Article received: 14.07. 2025
Article accepted: 09.09. 2025
Photostability study
of bimetallic terbium
and europium tetrafluoroterephthalates with phenanthroline
for application in thermometry
The luminescent thermometers based on lanthanide (Ln) complexes are of considerable interest for various fields of application requiring accurate temperature control, due to their high sensitivity, spatial resolution, and possible contactless and remote measurement of characteristics [1–13]. In microelectronics and nanoelectronics, these materials are indispensable for real-time monitoring local overheating in the “hot spots” of integrated circuits, processors, power semiconductor devices, and light-emitting diodes. Thin (50–100 μm), transparent, and flexible polymer films with a sensor can be deposited directly to the studied surfaces of chips or heat sinks, while providing high spatial resolution (determined by the optical detection system), non-invasiveness, resistance to electromagnetic interference, and operation in the range of 25–100 °C and higher. In the field of biomedical research and diagnostics, the nanoparticles of complexes or thin sensor layers open up space for measuring intracellular temperature or temperature near the biological samples under a microscope. This is facilitated by the component biocompatibility, possible excitation in the near UV range (365–405 nm) and bioimaging capabilities. For aviation and space technology, the composite films based on polymers and luminescent complexes offer a solution for thermal monitoring of structural elements on the surface or inside the composites under the extreme conditions of vibration, vacuum or aggressive environments. In this case, the key advantages include the composite mechanical strength and flexibility, its high thermal resistance and photostability, as well as chemical inertness. In the optical materials science and non-destructive testing, such developments allow mapping the temperature fields by developing the thermosensitive coatings or incorporating sensor particles into the transparent polymers. Such activity visualizes the temperature distribution in the optical elements, microfluidic chips or in the case of local laser heating by using the optical matrix transparency, high sensitivity (up to 2.50%/°C) and fast response.
The transition to bimetallic phosphors overcomes the main constraint of luminescent thermometry, namely the time-dependent signal instability. It leads to the basis for a new sensor generation, when the requirements for long-term reliability are comparable with the need for accuracy, especially under conditions of continuous optical monitoring or aggressive environments. Among all luminescent compounds of lanthanides, special attention is paid to the soluble and stable coordination compounds (CCs) of terbium (Tb3+) and europium (Eu3+) that demonstrate intense narrow-band luminescence in the visible range [1, 14–19].
Despite the higher sensitivity in the case of mixtures of monometallic Tb3+ and Eu3+ CCs, one of the key issues in their use is different photostability, leading to a change in the intensity ratio of their emission bands over time and, as a consequence, to the temperature signal distortion [17, 19–21]. In this regard, a promising area seems to be the development of bimetallic complexes in which both lanthanide ions are located in a single structure that can ensure synchronous degradation of their luminescent centers and signal stability [1–2, 7–9, 20]. In addition, for the practical application of luminescent sensors, their integration into the polymer matrices is important, since it ensures mechanical stability, ease of processing and possible obtaining of the flexible films [7–8].
In this paper, the influence of structural factors on photostability and preservation of thermometric specifications was studied using the monometallic [Ln(TFTA)3(Phen)2] ∙ 2H2O (Ln = Tb3+, Eu3+) and bimetallic [EuxTb1‑x(TFTA)3(Phen)2] ∙ 2H2O complexes as an example. Tetrafluoroterephthalic acid (H2TFTA) and phenanthroline (Phen) were selected as the ligands, while providing efficient energy transfer to the Ln3+ ions [22–23]. Polyimide PI2050 and polystyrene were used as the polymer matrices, since they combined high optical transparency, chemical inertness and high mechanical stability.
The mono- and bimetallic complexes were synthesized using a modified method [22]. The powder XRD of the synthesized compounds (Fig. 1a) showed their complete compliance with the structural data given in the references [24]. All reflections on the diffraction patterns completely coincided with the design values for the monoclinic syngony (crystal system) (space group C2 or C2/m). The thermogravimetric analysis of [Tb2(TFTA)3(Phen)2] ∙ 2H2O (Fig. 1b) revealed a three-stage decomposition process of the complexes in accordance with the crystallization water removal (n = 2.3 ± 0.3, 85–135 °C), the elimination of phenanthroline molecules (235–340 °C) and the carboxylate fragment decomposition (407–534 °C). The scanning electron microscopy (Fig. 1c) did not find any significant differences in the particle morphology of bimetallic complexes with various Tb : Eu ratios. In both cases, the agglomerated particles with the dimensions of 50–500 nm were observed.
To obtain the polymer composites, two types of matrices were selected, namely polyimide PI2050 and polystyrene (PS). Both matrices have high thermal stability, however, polystyrene melts at the temperature of 240 °C. In addition, a solvent is required to prepare the PS-based composites that increases the preparation time of the composite material from several hours to several days depending on the product thickness, and the composite materials are more fragile and less even (Fig. 1d left). Although the composites based on PI2050 require UV irradiation for curing, they do not need any handling of solvents, can be prepared in a few tens of minutes and are thin, smooth, and flexible (Fig. 1d right).
The study of luminescent properties have determined that the luminescence spectra of monometallic complexes (Fig. 2a) demonstrate the transitions typical for the Tb3+ (5D4→7FJ, J = 6–3) and Eu3+ (5D0→7FJ, J = 0–4) ions. The intensity ratio of the main bands of Tb3+ and Eu3+ is changed smoothly with variation in the complex composition (Fig. 2a) that confirms their possible fine-tuning of luminescent characteristics. In this case, the typical transitions of the europium ion are preserved in the luminescence spectra of bimetallic complexes (Fig. 2a) even at its minimum content (0.01 at. %, or x = 0.0001). This fact indicates a high efficiency of energy transfer between the Tb3+→Eu3+ ions. Comparison of the complex spectra in powder form and in the polymer matrices demonstrated their complete correspondence.
The photostability studies (Fig. 2f–h) revealed significant differences in the behavior of monometallic complexes. At the room temperature and constant UV irradiation (λex = 365 nm, power = 15 W), the terbium complex loses 27% of the initial luminescence intensity in 200 minutes, while the europium complex loses 34%. This difference may be due to several factors: 1) various stability of coordination spheres of the Tb3+ and Eu3+ ions to the photochemical processes; 2) possible participation of the excited Tb3+ states in the photochemical reactions; 3) different efficiency of luminescence quenching by the molecular oxygen. It is noteworthy that the XRD analysis of the complexes before and after photodegradation did not reveal any changes in the crystal structure of either the terbium or europium complexes that indicated the preserved coordination sphere of the lanthanide ions and pointed to the molecular nature of degradation processes.
Furthermore, the study of bimetallic complexes even at elevated temperature (100 °C) demonstrated (Fig. 2g–h) that although the overall luminescence intensity decreases over time, the intensity ratio of terbium and europium transitions (LIR = I(690 nm)/I(545 nm)) remains practically unchanged throughout the entire observation period (40 min). This important observation confirms the prospective application of bimetallic complexes for thermometry, since their readings will not be distorted over time due to the photodegradation process.
The temperature dependences of luminescence (Fig. 2f) demonstrate the behavior typical for the lanthanide complexes: when the temperature is increased, the terbium band intensity decreases faster than that of europium that is due to various thermal quenching efficiencies of their excited states. The temperature dependence of LIR (Fig. 2g–h) is linear in the studied range (20–100 °C), and the temperature sensitivity (S = d(LIR)/dT ∙ 100%) reaches 2.50%/°C for the composite based on [(Eu0.0001Tb0.9999)2(TFTA)3Phen2] ∙ 2H2O in PI2050. It is important to note that the temperature sensitivity of LIR in the composites remains almost at the same level as for the initial complexes that confirms their promising use for the development of polymeric heat-sensitive materials.
Thus, the conducted research allowed to develop a new grade of bimetallic luminescent materials based on the coordination compounds of terbium and europium with tetrafluoroterephthalic acid and phenanthroline that has the unique properties for application in optical thermometry. The main achievement of this paper was the establishment of a fundamental difference in photostability of the mono- and bimetallic complexes: if individual Tb3+ and Eu3+ complexes demonstrate various photodegradation rates (27% and 34% in 40 minutes), then the bimetallic systems maintain a stable intensity ratio of their typical transitions even at the elevated temperatures. This effect, along with the high sensitivity of the luminescence intensity ratio to the temperature (up to 2.50%/°C) makes the developed materials promising for the precise luminescent thermometers. An important practical result was the successful integration of complexes into the polymer matrices that ensured the formation of mechanically strong, flexible and thermally stable films with the preserved functional characteristics of the complexes.
FUNDING
The works were performed with the support of the Educational Program in Practical Chemistry implemented at the Sirius Educational Center.
AUTHORS
Anastasia V. Orlova – PhD student, Faculty of the Material Science, Lomonosov Moscow State University, Moscow, Russia. E-mail: lea.rosa.17@mail.ru.
ORCID 0000-0003-2534-2835
Liubov O. Tcelykh –PhD student, Department of Chemistry Lomonosov Moscow State University, Moscow, Russia. E-mail: tcelykh@my.msu.ru.
ORCID 0000-0002-1250-4017
Daniil S. Koshelev – Cand. of Sc. (Chemistry), Junior Research Fellow, Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia, E-mail: koshelevds@my.msu.ru
ORCID 0000-0001-8210-6690
Anton V. Bulatov – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: toni.bulatov.07@mail.ru.
ORCID 0009-0005-2412-9145
Milena R. Garbuzova – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: garbuzovamilenka@gmail.com.
ORCID 0009-0007-7108-3455
Kirill R. Zezyulya – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: kirillzezyulya@gmail.com
ORCID 0009-0001-2582-479X
Evgenii D. Marshev – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: marshev07@bk.ru.
ORCID 0009-0001-6089-7695
Lada S. Rubanova – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: lada.rubanova.00@mail.ru.
ORCID 0009-0002-0425-5046
Timofei L. Tsymbal – Sirius Education Center, Federal Territory «Sirius», Russia. E-mail: cymbalt112@gmail.com.
ORCID 0009-0003-4695-4045
Valentina V. Utocnikova – Dr. of Science, Prof. Faculty of the Material Science, Lomonosov Moscow State University, Moscow, Russia. E-mail: valentina@utochnikova.ru.
ORCID 0000-0002-0830-1268
AUTHOR CONTRIBUTIONS
Anastasia Orlova: Visualization, Writing – review & editing, Project administration; Liubov Tcelykh: Visualization, Writing – original draft, Writing – review & editing; Daniil Koshelev: Writing – review & editing, Methodology, Formal analysis; Anton Bulatov: Investigation; Milena Garbuzova: Investigation; Kirill Zezyulya: Investigation; Evgenii Marshev: Investigation; Lada Rubanova: Investigation; Timofei Tsymbal: Investigation; Valentina V. Utocnikova: Writing – review & editing, Project administration, Conceptualization, Funding acquisition.
Conflicts of Interest
The authors declare no conflicts of interest.
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