First principles impurity diffusion coefficients

Mantina, Manjeera; Wang, Yi; Chen, Lei; Liu, Zhe; Wolverton, Christopher

doi:10.1016/j.actamat.2009.05.006

Cited by 246 publications

(137 citation statements)

References 42 publications

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“…The empirical Arrhenius equation, which describes the temperature dependence of reaction rates, can also be applied to model that of diffusion coefficients. 41,42 The linear relationship between the natural logarithm of the diffusion coefficients of BFRs and the reciprocal of temperature on Figure 4 suggests that the temperature dependence of the diffusion coefficients of BFRs conforms to the Arrhenius equation. The apparent activation energy (E a , J·mol −1 ) for diffusion of BFR molecules in the plastic matrix is thus estimated as…”

Section: Environmental Science and Technologymentioning

confidence: 99%

Kinetics of Brominated Flame Retardant (BFR) Releases from Granules of Waste Plastics

Sun

Cheng

et al. 2016

Environ. Sci. Technol.

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Plastic components of e-waste contain high levels of brominated flame retardants (BFRs), whose releases cause environmental and human health concerns. This study characterized the release kinetics of polybrominated diphenyl ethers (PBDEs) from millimeter-sized granules processed from the plastic exteriors of two scrap computer displays at environmentally relevant temperatures. The release rate of a substitute of PBDEs, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), from the waste plastics, was reported for the first time. Deca-BDE was the most abundant PBDE congeners in both materials (87−89%), while BTBPE was also present at relatively high contents. The release kinetics of BFRs could be modeled as one-dimensional diffusion, while the temperature dependence of diffusion coefficients was well described by the Arrhenius equation. The diffusion coefficients of BFRs (at 30°C) in the plastic matrices were estimated to be in the range of 10 −27.16 to 10 −19.96 m 2 ·s −1 , with apparent activation energies between 88.4 and 154.2 kJ·mol −1 . The half-lives of BFR releases (i.e., 50% depletion) from the plastic granules ranged from thousands to tens of billions of years at ambient temperatures. These findings suggest that BFRs are released very slowly from the matrices of waste plastics through molecular diffusion, while their emissions can be significantly enhanced with wear-and-tear and pulverization.

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Section: Environmental Science and Technologymentioning

confidence: 99%

Kinetics of Brominated Flame Retardant (BFR) Releases from Granules of Waste Plastics

Sun

Cheng

et al. 2016

Environ. Sci. Technol.

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“…kinetics [34,[39][40][41]. Cu also shows an attractive solute-vacancy binding energy [26,42]. Assuming that Cu stays dissolved in the fcc Step (i) is applicable to any Al-Mg-Si alloy.…”

Section: ) As Being Primarily Influenced By the Early Clustering mentioning

confidence: 99%

Design strategy for controlled natural aging in Al–Mg–Si alloys

Werinos

Antrekowitsch

Ebner³

et al. 2016

Acta Materialia

112

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This study presents a design strategy for Al-Mg-Si alloys to control natural aging. Recently, trace addition of Sn was shown to suppress natural aging for up to two weeks, which was explained by the strong trapping of vacancies to Sn atoms. Here we explore the effect of Keywords: aluminum alloys, natural aging, phase transformation kinetics, vacancies, trace elements This is a pre-print of the following article: Werinos, M.; Antrekowitsch, H.; Ebner, T.; Prillhofer, R.; Curtin, W. A.; Uggowitzer, P. J.; Pogatscher, S. Acta Mater. 2016, 118, 296-305.. The formal publication is available at http://dx

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“…In the present work, the temperature dependence of the correlation factor, ݂ ଶ and the activation energy for diffusion is calculated as [6,31] ܳ ൌ ‫ܧ∆‬ ‫ܧ߂−‬ + ‫ܧ߂‬…”

Section: Diffusion Coefficient Calculationmentioning

confidence: 99%

“…Diffusion properties [6][7], elastic constants [8], and stacking fault energies are all properties that can be calculated via first-principles calculations based on density functional theory at 0 K and all contribute to the creep process [4] in different ways. For example, elastic constants are important in understanding how the system will elastically deform, and can give other information on interatomic bonding [9] and mechanical stability [10].…”

Section: Introductionmentioning

confidence: 99%

Effects of Alloying Elements on Elastic, Stacking Fault and Diffusion Properties of Fcc Ni from First-principles: Implications for Tailoring the Creep Rate of Ni-base Superalloys

Zacherl¹,

Shang²,

Kim³

et al. 2012

Superalloys 2012 (Twelfth International Symposium)

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To understand the effects of alloying elements on the creep rate of Ni-base superalloys, factors entering into a secondary creep rate are calculated via first-principles calculations based on density functional theory for 26 Ni 31 X systems where X = Al, Co, Cr, Cu, Fe, Hf, Ir, Mn, Mo, Nb, Os, Pd, Pt, Re, Rh, Ru, Sc, Si, Ta, Tc, Ti, V, W, Y, Zr, and Zn. They are volume, elastic properties, stacking fault energy, and diffusivity. It is found that shear modulus, Young's modulus, and roughly stacking fault energy show inverse correlation to the atomic volume of the system. In addition, the closer the alloying elements to Ni, with respect to atomic volume and atomic number, the larger the predicted shear modulus, Young's modulus, and stacking fault energy. Diffusivity calculations show that mid-row 5d transition metal elements, particularly Re, Os, and Ir, have the highest activation barrier for diffusion, while far-right or far-left row placement elements such as Y, Zn, and Hf, have the lowest activation energy barriers for diffusion. A creep rate ratio of ߝሶ ே యభ ߝሶ ே ⁄ is calculated and the effect of the alloying elements shows 13 systems have a decreased creep rate relative to Ni, while 13 systems have an increased creep rate relative to Ni.

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First principles impurity diffusion coefficients

Cited by 246 publications

References 42 publications

Kinetics of Brominated Flame Retardant (BFR) Releases from Granules of Waste Plastics

Kinetics of Brominated Flame Retardant (BFR) Releases from Granules of Waste Plastics

Design strategy for controlled natural aging in Al–Mg–Si alloys

Effects of Alloying Elements on Elastic, Stacking Fault and Diffusion Properties of Fcc Ni from First-principles: Implications for Tailoring the Creep Rate of Ni-base Superalloys

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