A first-principles study of self-diffusion coefficients of fcc Ni

Hargather, Chelsey Z.; Shang, Shun‐Li; Liu, Zhe; Du, Yong

doi:10.1016/j.commatsci.2014.01.003

Cited by 46 publications

(32 citation statements)

References 47 publications

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“…On the theory side, numerous density functional theory (DFT) studies have been reported to estimate the monovacancy formation enthalpy in fcc Ni, but they considered only the T = 0 K limit (Table II). The temperature dependence of the ab initio Gibbs energy of vacancy formation was determined only within the low-temperature quasiharmonic approximation [11,12]. Corresponding results [11,12] suggest the entropy of formation to be negative (Table II), in clear contrast to the positive DD data (Table I).…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of the Gibbs energy of vacancy formation of fcc Ni

et al. 2018

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Quantum-mechanical calculations are used to determine the temperature dependence of the Gibbs energy of vacancy formation in nickel. Existing data reveal a discrepancy between the high-temperature estimates from experiments and low-temperature approximations from density functional theory. Our finite-temperature calculations-which include the effects of magnetism and fully interacting phonon vibrations-demonstrate that this discrepancy is mostly caused by the previously neglected explicit anharmonic contribution.

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Section: Introductionmentioning

confidence: 99%

Temperature dependence of the Gibbs energy of vacancy formation of fcc Ni

et al. 2018

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“…TST has become a practical tool in the context of DFT calculations when efficient algorithms for finding the minimum-energy path have been developed, such as the nudged elastic band (NEB) and the climb image nudged elastic band (CI-NEB) method [17]. At present, first-principles calculations of diffusion coefficients are largely limited to cubic systems, such as those in Al [15,18], Fe [19,20], and Ni [21][22][23] alloys. This is due to the additional complexity of anisotropy associated with the calculations of diffusion coefficients in hcp systems.…”

Section: Introductionmentioning

confidence: 99%

Diffusion coefficients of alloying elements in dilute Mg alloys: A comprehensive first-principles study

et al. 2016

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First-principles calculations based on density functional theory have been used to calculate the temperature-dependent dilute tracer diffusion coefficients for 47 substitutional alloying elements in hexagonal closed packed (hcp) Mg by combining transition state theory and an 8-frequency model. The minimum energy pathways and the saddle point configurations during solute migration are calculated with the climbing image nudged elastic band method. Vibrational properties are obtained using the quasi-harmonic Debye model with inputs from first-principles calculations. An improved generalized gradient approximation of PBEsol is used in the present first-principles calculations, which is able to well describe both vacancy formation energies and vibrational properties. It is found that the solute diffusion coefficients in dilute hcp Mg are roughly inversely proportional to bulk modulus, which reflects the solutes' bonding to Mg. Transition metal elements with d electrons show strong interactions with Mg and have large diffusion activation energies. Correlation effects are not negligible for solutes Ca, Na, Sr, Se, Te, and Y, in which the direct solute migration barriers are much smaller than the solvent (Mg) migration barriers. Calculated diffusion coefficients are in remarkable agreement with available experimental data in the literature.

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“…For example, the vacancy formation Gibbs energies of Al and Cu as a function of temperature, ), were studied in Neugebauer's group [4,23]. We developed approaches for predicting the self and impurity diffusion coefficients in Al, Cu, Fe, Mg, Ni, and Ti alloys with bcc, fcc, or hcp structure based on the vacancy-mediated diffusion mechanism [2,8,[25][26][27][28][29][30][31][32][33][34],…”

Section: Introductionmentioning

confidence: 99%

A comprehensive first-principles study of pure elements: Vacancy formation and migration energies and self-diffusion coefficients

et al. 2016

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A vast number of materials properties and phenomena are regulated by diffusion. However, diffusion coefficients from experiments and calculations are far from complete. Here, we report a compilation of vacancy formation energies ( ), vacancy migration energies ( ), vacancy activation energies ( ), vacancy concentrations (C Va ), and vacancy-mediated self-diffusion coefficients (D Va ) as a function of temperature for 82 pure elements in bcc, fcc, and hcp structures by means of a comprehensive first-principles study. We assess the accuracy of four exchange-correlation (X-C) functionals for first-principles calculations, including the local density approximation (LDA), two generalized gradient approximations (PW91 and PBE), andPBEsol  the focus of the present work. To gain temperature-dependent diffusion properties, transition state structure searches are performed by the climbing image nudged elastic band

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A first-principles study of self-diffusion coefficients of fcc Ni

Cited by 46 publications

References 47 publications

Temperature dependence of the Gibbs energy of vacancy formation of fcc Ni

Temperature dependence of the Gibbs energy of vacancy formation of fcc Ni

Diffusion coefficients of alloying elements in dilute Mg alloys: A comprehensive first-principles study

A comprehensive first-principles study of pure elements: Vacancy formation and migration energies and self-diffusion coefficients

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