Point defects stabilise cubic Mo-N and Ta-N

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F16%3A00091306" target="_blank" >RIV/00216224:14310/16:00091306 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216305:26210/16:PU119817

Výsledek na webu

<a href="http://dx.doi.org/10.1088/0022-3727/49/37/375303" target="_blank" >http://dx.doi.org/10.1088/0022-3727/49/37/375303</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/0022-3727/49/37/375303" target="_blank" >10.1088/0022-3727/49/37/375303</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Point defects stabilise cubic Mo-N and Ta-N

Popis výsledku v původním jazyce

We employ ab initio calculations to investigate energetics of point defects in metastable rocksalt cubic Ta-N and Mo-N. Our results reveal a strong tendency to off-stoichiometry, i.e. defected structures are surprisingly predicted to be more stable than perfect ones with 1 : 1 metal-to-nitrogen stoichiometry. Despite the similarity of Ta-N and Mo-N systems in exhibiting this unusual behaviour, we also point out their crucial differences. While Ta-N significantly favours metal vacancies, Mo-N exhibits similar energies of formation regardless of the vacancy type (V-Mo, V-N) as long as their concentration is below approximate to 15 at.%. The overall lowest energies of formation were obtained for Ta0.78N and Mo0.91N, which are hence predicted to be the most stable compositions. To account for various experimental conditions during synthesis, we further evaluated the phase stability as a function of chemical potential of individual species. The proposed phase diagrams reveal four stable compositions, Mo0.

Název v anglickém jazyce

Point defects stabilise cubic Mo-N and Ta-N

Popis výsledku anglicky

We employ ab initio calculations to investigate energetics of point defects in metastable rocksalt cubic Ta-N and Mo-N. Our results reveal a strong tendency to off-stoichiometry, i.e. defected structures are surprisingly predicted to be more stable than perfect ones with 1 : 1 metal-to-nitrogen stoichiometry. Despite the similarity of Ta-N and Mo-N systems in exhibiting this unusual behaviour, we also point out their crucial differences. While Ta-N significantly favours metal vacancies, Mo-N exhibits similar energies of formation regardless of the vacancy type (V-Mo, V-N) as long as their concentration is below approximate to 15 at.%. The overall lowest energies of formation were obtained for Ta0.78N and Mo0.91N, which are hence predicted to be the most stable compositions. To account for various experimental conditions during synthesis, we further evaluated the phase stability as a function of chemical potential of individual species. The proposed phase diagrams reveal four stable compositions, Mo0.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

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Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Journal of physics D: Applied physics

ISSN

0022-3727

e-ISSN

—

Svazek periodika

49

Číslo periodika v rámci svazku

37

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

8

Strana od-do

"nestrankovano"

Kód UT WoS článku

000384093000022

EID výsledku v databázi Scopus

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