Characteristics of Hf(M)SiBCN (M = Y, Ho, Ta, Mo) Coatings: Role of the M Choice

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23520%2F21%3A43963137" target="_blank" >RIV/49777513:23520/21:43963137 - isvavai.cz</a>

Alternative codes found

RIV/49777513:23640/21:43963137

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Characteristics of Hf(M)SiBCN (M = Y, Ho, Ta, Mo) Coatings: Role of the M Choice

Original language description

Thin films based on light main group elements are attractive due to a unique combination of properties ranging from high hardness through optical transparency to high temperature stability and oxidation resistance. The properties, in the first place electrical conductivity, can be further modulated by addition of early transition metals. Properties of amorphous Hf(M)SiBCN films are investigated by combining their preparation using pulsed magnetron sputtering of boron rich composite targets B4C‒Hf‒M‒Si (45‒65% B4C, 15‒20% Hf, 5% Y/Hf/Ho/Ta/Mo, 15‒30% Si) in 85% Ar + 15% N2 discharge gas mixture with ab-initio calculations. First, we study the effect of the M choice and fraction on calculated mechanical properties and formation energy (Eform) of binary MN and ternary HfxM1–xN crystals. We discuss the dependence of Eform on the crystal structure and on the distribution of Hf and M in the metal sublattice. The calculated mechanical properties of MN (rather than HfxM1–xN) very well correlate with measured mechanical properties of a-HfMSiBCN. The driving force towards N incorporation, monotonically decreasing with increasing periodic table group number of M according to the calculated Eform of MN, very well correlates with measured electrical conductivity and extinction coefficient of a-HfMSiBCN. Second, we use ab initio molecular dynamics to model the a-HfMSiBCN materials of experimental compositions and densities themselves. The calculated band gap, localisation of states around the Fermi level and bonding preferences of the M element (in particular the tendency of the M element to bind with N) also correlate with the measured increasing metallicity with respect to the periodic table group number of M, and confirm the possibility of predicting the trends of characteristics of a-HfMSiBCN using those of MN. Third, we study the a-HfMSiBCN properties as a function of each other, and we identify an optimum target composition (B4C covered by 15% Hf, 5% Ta and 15‒20% Si) leading to hard (&gt;20 GPa) films with relatively high conductivity at a given extinction coefficient and vice versa. The results are important for the design of hard, conductive and/or transparent high temperature coatings.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20506 - Coating and films

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2021

Confidentiality

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