&lt;I&gt;Ab Initio&lt;/I&gt; Molecular Dynamics Study of Fe Adsorption on TiN (001) Surface

Wang, Chao; Dai, Yong; Gao, Haiyan; Ruan, Xiaoming; Wang, Jun; Sun, Baode

doi:10.2320/matertrans.m2010244

Cited by 11 publications

(5 citation statements)

References 17 publications

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“…However, ab initio molecular dynamics (AIMD) allows for quantum mechanical-based calculations to be performed at non-zero temperatures. AIMD has been utilized to study a variety of systems including liquid phase diffusion in Al-Si (Manga and Poirier, 2018), the adsorption energy of Fe on TiN surfaces (Wang et al, 2010), NaCl dissolution in water (Timko et al, 2010) and finite temperature phonon dispersion curves in bcc Zr and bcc (Li Hellman et al, 2011). Hood et al (2008) have previously utilized AIMD to study the equation of state of U and the variation in density of states for the liquid phase of U at two unique temperatures.…”

Section: Introductionmentioning

confidence: 99%

Determination of Thermal Expansion, Defect Formation Energy, and Defect-Induced Strain of α-U Via ab Initio Molecular Dynamics

et al. 2021

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Uranium (U) is often alloyed with molybdenum (Mo) or zirconium (Zr) in order to stabilize its high-temperature body-centered cubic phase for use in nuclear reactors. However, in all metallic fuel forms, the α phase of U remains in some fraction. This phase decomposition due to temperature or compositional variance can play an outsized role on fuel performance and microstructural evolution. Relatively little is known about fundamental point defect properties in α-U at non-zero temperatures, from either computational or experimental studies. This work performs the first thorough evaluation of the α phase of U via ab initio molecular dynamics (AIMD). A number of thermophysical properties are calculated as a function of temperature, including equilibrium lattice parameters, thermal expansion, and heat capacity. These results indicate a two-region behavior, with the transition at 400 K. The thermal expansion/contraction in the a/b direction occurs rapidly from 100 up to 400 K, after which a more linear and gradual change in the lattice constant takes place. The volumetric expansion matches experiments quantitatively, but the individual lattice constant expansion only matches experiments qualitatively. Point defect formation energies and induced lattice strains are also determined as a function of temperature, providing insight on defect populations and the fundamentals of irradiation growth in α-U. Interstitials induce significantly more strain than vacancies, and the nature of that strain is highly dependent on the individual lattice directions. The direction of point defect-induced lattice strain is contrary to the irradiation growth behavior of α-U. This work shows that isolated point defects cannot be the primary driving force responsible for the significant irradiation-induced growth of α-U observed experimentally.

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Section: Introductionmentioning

confidence: 99%

Determination of Thermal Expansion, Defect Formation Energy, and Defect-Induced Strain of α-U Via ab Initio Molecular Dynamics

et al. 2021

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“…First, we testify that the Fe atom prefers to be in the C-top position, but not above the M atom or bridge site, as was also obtained in [22] for Fe on (0 0 1)TiN. Table 1.…”

Section: Fe Adsorption On the (0 0 1)mx Surfacementioning

confidence: 91%

“…Ab initio calculations of the Fe adsorption on the (0 0 1)TiN surface were performed to understand the nucleation mechanism of Fe on the TiN particles [22]. These calculations demonstrated that adsorption energy is a reliable parameter to describe a first stage of nucleation and the knowledge of adsorption properties of carbides and nitrides is important to predict the efficient precipitates in steel.…”

Section: Introductionmentioning

confidence: 99%

Ab initio study of Fe adsorption on the (001) surface of transition metal carbides and nitrides

Lekakh

Medvedeva

2015

Computational Materials Science

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“…The adsorption energy on the WO 3 surface varied in a range of −1.25-0.97 eV/atom, depending on the types of adsorbates (NO, CO, or H 2 O) [71][72][73][74][75], while those of NO and CO 2 on the TiO 2 surface were in a narrow range of 0.03-0.74 eV/atom [76][77][78]. As for the nitride surfaces, the adsorption sites obviously impact the adsorption energies [79][80][81]. The interaction between oxygen/H 2 O molecules and the metal atoms in the nitrides was considerably stronger, resulting in a lower adsorption energy [80,81].…”

Section: Frictionmentioning

confidence: 99%

High-temperature wear mechanisms of TiNbWN films: Role of nanocrystalline oxides formation

Chen

Zhang

et al. 2022

Friction

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Refractory high/medium entropy nitrides (HENs/MENs) exhibit comprehensive application prospects as protective films on mechanical parts, particularly those subjected to sliding contacts at elevated temperatures. In this study, a new MEN system TiNbWN, forming a single fcc solution, is designed and its wear performance at temperatures ranging from 25 to 750 °C is explored. The wear mechanisms can be rationalized by examining the subsurface microstructural evolutions using the transmission electron microscopy as well as calculating the phase diagrams and interfacial adhesion behavior employing calculation of phase diagram (CALPHAD) and density functional theory (DFT). To be specific, increased wear losses occur in a temperature range of 25–600 °C, being predominantly caused by the thermally-induced hardness degradation; whereas at the ultimate temperature (750 °C), the wear loss is refrained due to the formation of nanocrystalline oxides (WnO3n−2, TiO2, and γTiOx), as synergistically revealed by microscopy and CALPHAD, which not only enhance the mechanical properties of the pristine nitride film, but also act as solid lubricants, reducing the interfacial adhesion. Thus, our work delineates the role of the in situ formed nanocrystalline oxides in the wear mechanism transition of TiNbWN thin films, which could shed light on the high-temperature wear behavior of refractory HEN/MEN films.

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<I>Ab Initio</I> Molecular Dynamics Study of Fe Adsorption on TiN (001) Surface

Cited by 11 publications

References 17 publications

Determination of Thermal Expansion, Defect Formation Energy, and Defect-Induced Strain of α-U Via ab Initio Molecular Dynamics

Determination of Thermal Expansion, Defect Formation Energy, and Defect-Induced Strain of α-U Via ab Initio Molecular Dynamics

Ab initio study of Fe adsorption on the (001) surface of transition metal carbides and nitrides

High-temperature wear mechanisms of TiNbWN films: Role of nanocrystalline oxides formation

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