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Keyword: zro2

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    Preparation, phase and optical characterization of Sm2O3-ZrO2 coatings on glasses obtained by sol-gel technology using the Dip Coating method

    • Stancho Yordanov
    • Mariela Dimitrova
    • Shaban Uzun
    • Vladimir Petkov
    • Bojidar Jivov
    • Tatyana Ivanova
    Industry 4.0, Vol. 10 (2025), Issue 3, pg(s) 103-106
    • Abstract
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    Obtained experimental self-cleaning coatings (based on compositions with the participation of Sm2O3), applied by the sol-gel method on glass slides. This study attempts to improve the overall efficiency of a photovoltaic solar panel by using a Sm2O3 doped ZrO2 (SDZ)-based coating. The optical characterization and phase composition of the obtained experimental samples were investigated using UVVIS- NIR, XRD and XRF methods. The coatings are nanocrystalline according to XRD and XRF analyzes and show transmittance close to that of pure glass when tested with a UV–VIS–NIR spectrophotometer The experimental results represent a prerequisite for the development of a series of additional compositions and a detailed technological regime for obtaining various modifications of resistant, long-lasting selfcleaning coatings, potentially applicable to photovoltaic panels.

  • TECHNOLOGIES

    Study of the influence of transition and rare earth oxide coatings on glasses for photovoltaic panels produced by the sol-gel method. A Review

    • Stancho Yordanov
    • Vladimir Petkov
    • Mihaela Aleksandrova
    • Bojidar Jivov
    Machines. Technologies. Materials., Vol. 19 (2025), Issue 6, pg(s) 225-228
    • Abstract
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    The efficiency of photovoltaic (PV) systems is significantly influenced by surface contamination, which can reduce light transmission and energy conversion performance. In this study, self-cleaning nanostructured coatings based on titanium dioxide (TiO₂ ), zirconium dioxide (ZrO₂ ), and their doped and composite variants (with Y₂ O₃ and Eu₂ O₃ ) were synthesized using the sol-gel method and applied to photovoltaic glass substrates. The coatings were characterized in terms of their optical transmittance, surface morphology (AFM), wettability (contact angle), and crystallographic properties (XRD). Results indicate that TiO₂ coatings offer superior superhydrophilic behavior, while stabilized ZrO₂ -based composites show excellent transparency, surface homogeneity, and long-term durability. Eu₂ O₃ -doped coatings exhibit additional luminescent functionalities, potentially useful for photonic enhancement. These findings highlight the potential of sol-gel coatings in improving PV panel performance via integrated passive cleaning mechanisms and multifunctional surface engineering.

  • INNOVATIVE SOLUTIONS

    Photoluminescence properties of coatings on A356 containing Al2O3, Sm2O3 and ZrO2 synthesized by zol-gel technology

    • Angel Velikov
    • Stancho Yordanov
    • Vladimir Petkov
    • Shaban Uzun
    • Boiko Krastev
    Innovations, Vol. 13 (2025), Issue 1, pg(s) 34-36
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    Thin coatings of aluminum oxide (Al2O3), zirconium oxide (ZrO2) and samarium oxide (Sm2O3) on aluminum alloy Al7SiMg (A356) were prepared by sol-gel method and immersion technique. The materials were characterized in detail by X-ray diffraction. The luminescent properties at room temperature were also investigated. Luminescence analysis showed that the Al2O3 coating containing ZrO2 exhibits broad excitation and emission bands, peaking at 328 nm and 392 nm, respectively. Photoluminescence data for the Al2O3 coating containing ZrO2 and Sm2O3 indicated effective excitation at 404 nm and strong broadband emission, which is due to the co-emission of ZrO2 and Sm2O3. Chromaticity coordinate analysis revealed that Al2O3 coating containing ZrO2 and Al2O3 coating containing ZrO2 and Sm₂ O₃ emit in the blue-purple and pale pink regions, respectively.The chromaticity coordinates, color purity and CIE (Commission Internationale de L’Eclairage) color-correlated temperature were determined.

  • MATERIALS

    Luminescent properties of sol-gel synthesized ZrO2 and Sm2O3 coatings on glass

    • Stancho Yordanov
    • Mihaela Aleksandrova
    • Vladimir Petkov
    • Shaban Usun
    • Mariana Pavlova
    Machines. Technologies. Materials., Vol. 19 (2025), Issue 4, pg(s) 146-149
    • Abstract
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    Thin coatings of zirconia oxide (ZrO2) and samarium oxide (Sm2O3) on glass have been prepared by using sol-gel method and dip coating technique. Materials were characterized in detail by X-ray diffraction. The luminescent properties at room temperature were also investigated. Excitation and emission spectra of ZrO2 coating consists of broad bands with maximums at 318 and 365 nm respectively.
    The photoluminescence measurements of samarium coating suggest that can be efficiently excited with 700 nm and consist of emission bands centered at 567, 603, 639 and 707 nm, consistent with characteristic Sm3+ transitions. The CIE (Commission Internationale de L’Eclairage) chromatic coordinates, color purity and color correlated temperature were determined.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    Effect of zirconium dioxide on the obtaining of layers synthesized by zol-gel technology for photovoltaic applications

    • Stancho Yordanov
    • Silviya Simeonova
    • Sasho Vassilev
    • Vladimira Videva
    • Vladimir Petkov
    • Angel Velikov
    • Vladimir Blaskov
    • Boiko Krastev
    Industry 4.0, Vol. 8 (2023), Issue 8, pg(s) 398-400
    • Abstract
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    Thin films deposited on glass substrates by sol-gel containing ZrO2 show photocatalytic activity, which are compared with TiO2 – which is used as a standard photocatalytic material applied in photovoltaics. By modifying ZrO2, coatings on glass surfaces were obtained, which are characterized by high properties, which are a prerequisite for use in photovoltaics. The coatings are dense and nanocrystal line according to SEM and XRD studies and optically transparent according to UV-VIS-NIR spectra

  • TECHNOLOGIES

    Deposition of ZrO2 thin films obtained by sol-gel method on monolithic composite with layered structure of Nb30Ti/Al

    • Vladimir Petkov
    • Mihaela Aleksandrova
    • Vladimir Blaskov
    Machines. Technologies. Materials., Vol. 16 (2022), Issue 2, pg(s) 58-61
    • Abstract
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    The present publication is aimed at obtaining a stable sol from ZrO2 stabilized with Y2O3. The substrate on which the layers are deposited was developed by a team from Russia and is intermetalite with a layered structure Nb30Ti/Al. Deposition was performed by spinning with a Spin Coater Ossila L2001A3. The deposition sequence of the layers lasts 30 seconds. The finished carrier is dried at 120°C in an oven. It is heated in a laboratory furnace at 350oC. The results were characterized by XRD and SEM analyzes.

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