Vše

Co hledáte?

Vše
Projekty
Výsledky výzkumu
Subjekty

Rychlé hledání

  • Projekty podpořené TA ČR
  • Významné projekty
  • Projekty s nejvyšší státní podporou
  • Aktuálně běžící projekty

Chytré vyhledávání

  • Takto najdu konkrétní +slovo
  • Takto z výsledků -slovo zcela vynechám
  • “Takto můžu najít celou frázi”

Enhancement of high-temperature oxidation resistance and thermal stability of hard and optically transparent Hf‒B‒Si‒C‒N films by Y or Ho addition

Identifikátory výsledku

  • Kód výsledku v IS VaVaI

    <a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23520%2F21%3A43962658" target="_blank" >RIV/49777513:23520/21:43962658 - isvavai.cz</a>

  • Nalezeny alternativní kódy

    RIV/49777513:23640/21:43962658

  • Výsledek na webu

  • DOI - Digital Object Identifier

Alternativní jazyky

  • Jazyk výsledku

    angličtina

  • Název v původním jazyce

    Enhancement of high-temperature oxidation resistance and thermal stability of hard and optically transparent Hf‒B‒Si‒C‒N films by Y or Ho addition

  • Popis výsledku v původním jazyce

    Multielement ceramic coatings are appropriate candidates for high-temperature applications due to their excellent behavior at temperatures exceeding 1000 °C. When a very high oxidation resistance is combined with the thermal stability of a high optical transparency, they can be considered for high-temperature passive protection of optical and optoelectronic devices. Therefore, this work focuses on a systematic investigation of high-temperature behavior of Hf–B–Si–Y/Ho–C–N films with a high hardness and optical transparency The films were deposited using pulsed dc magnetron co-sputtering of a target consisting of a B4C plate overlapped by Hf, Si and Y or Ho stripes with the fixed 15% Hf + 50% Si + 5% Hf/Y/Ho fractions in the target erosion area in an argon-nitrogen gas mixture (25% N2 fraction) onto Si and SiC substrates heated to 450 °C and held at a floating potential. The oxidation resistance of the films in air (up to 1500 °C) and the thermal stability of their structure in inert gases (up to 1600 °C) were investigated by high-resolution thermogravimetry and differential scanning calorimetry. Other analytical techniques were employed to characterize changes in the structure and properties of the films after their heat-treatment. All as-deposited films were amorphous, highly optically transparent, electrically non-conductive and possessed a sufficiently high hardness (around 22 GPa) and low compressive stress (&lt; –1.5 GPa). Very low mass changes (around 25 µg/cm^2) were detected upon heating to 1500 °C in air. Hf6B12Si29Y2C2N45 and Hf5B13Si25Ho3C2N48 films exhibited a lower thickness of a protective surface oxide layer (194 nm and 202 nm, respectively) compared to a Hf6B10Si38C2N44 film (243 nm). The oxide layer was composed of HfO2 nanocrystallites of different structures embedded in an amorphous matrix. Heating of the films in helium up to 1100 °C resulted in an increase of their hardness while retaining optical transparency. In case of the Hf6B12Si29Y2C2N45 film, the hardness increased even up to 1300 °C and the film remained optically transparent up to 1400 °C. It was also found that the transformation of the amorphous structure to the crystalline one starts in all cases around 1400 °C at the film/substrate interface. The lowest thickness of the crystallizing zone was observed for the Hf6B12Si29Y2C2N45 film confirming its highest thermal stability among the films investigated. Multielement Hf-B-Si-Y/Ho-C-N films were proven to have a high potential to be good candidates as high-temperature protective coatings for optical and optoelectronic devices.

  • Název v anglickém jazyce

    Enhancement of high-temperature oxidation resistance and thermal stability of hard and optically transparent Hf‒B‒Si‒C‒N films by Y or Ho addition

  • Popis výsledku anglicky

    Multielement ceramic coatings are appropriate candidates for high-temperature applications due to their excellent behavior at temperatures exceeding 1000 °C. When a very high oxidation resistance is combined with the thermal stability of a high optical transparency, they can be considered for high-temperature passive protection of optical and optoelectronic devices. Therefore, this work focuses on a systematic investigation of high-temperature behavior of Hf–B–Si–Y/Ho–C–N films with a high hardness and optical transparency The films were deposited using pulsed dc magnetron co-sputtering of a target consisting of a B4C plate overlapped by Hf, Si and Y or Ho stripes with the fixed 15% Hf + 50% Si + 5% Hf/Y/Ho fractions in the target erosion area in an argon-nitrogen gas mixture (25% N2 fraction) onto Si and SiC substrates heated to 450 °C and held at a floating potential. The oxidation resistance of the films in air (up to 1500 °C) and the thermal stability of their structure in inert gases (up to 1600 °C) were investigated by high-resolution thermogravimetry and differential scanning calorimetry. Other analytical techniques were employed to characterize changes in the structure and properties of the films after their heat-treatment. All as-deposited films were amorphous, highly optically transparent, electrically non-conductive and possessed a sufficiently high hardness (around 22 GPa) and low compressive stress (&lt; –1.5 GPa). Very low mass changes (around 25 µg/cm^2) were detected upon heating to 1500 °C in air. Hf6B12Si29Y2C2N45 and Hf5B13Si25Ho3C2N48 films exhibited a lower thickness of a protective surface oxide layer (194 nm and 202 nm, respectively) compared to a Hf6B10Si38C2N44 film (243 nm). The oxide layer was composed of HfO2 nanocrystallites of different structures embedded in an amorphous matrix. Heating of the films in helium up to 1100 °C resulted in an increase of their hardness while retaining optical transparency. In case of the Hf6B12Si29Y2C2N45 film, the hardness increased even up to 1300 °C and the film remained optically transparent up to 1400 °C. It was also found that the transformation of the amorphous structure to the crystalline one starts in all cases around 1400 °C at the film/substrate interface. The lowest thickness of the crystallizing zone was observed for the Hf6B12Si29Y2C2N45 film confirming its highest thermal stability among the films investigated. Multielement Hf-B-Si-Y/Ho-C-N films were proven to have a high potential to be good candidates as high-temperature protective coatings for optical and optoelectronic devices.

Klasifikace

  • Druh

    O - Ostatní výsledky

  • CEP obor

  • OECD FORD obor

    20506 - Coating and films

Návaznosti výsledku

  • Projekt

  • Návaznosti

    S - Specificky vyzkum na vysokych skolach

Ostatní

  • Rok uplatnění

    2021

  • Kód důvěrnosti údajů

    S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů