Incorporating first-principles energetics in computational thermodynamics approaches

Wolverton, Chris; Yan, Xiaofeng; Vijayaraghavan, R.; Ozoliņš, Vidvuds

doi:10.1016/s1359-6454(01)00430-x

Cited by 92 publications

(42 citation statements)

References 27 publications

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“…In this hybrid approach, the energetics obtained through electronic structure calculations are used as input data within the CALPHAD formalism to obtain the parameters that describe the Gibbs energy of the system. 5 The first-principles electronic structure calculations of perfectly ordered periodic structures are relatively straightforward since they usually rely on the use of periodic boundary conditions. Problems arise, however, when attempting to use these methods to study the thermochemical properties of random solid solutions since an approximation must be made in order to simulate a random atomic configuration through a periodic structure.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic properties of binary hcp solution phases from special quasirandom structures

et al. 2006

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Three different special quasirandom structures ͑SQS's͒ of the substitutional hcp A 1−x B x binary random solutions ͑x = 0.25, 0.5, and 0.75͒ are presented. These structures are able to mimic the most important pair and multi-site correlation functions corresponding to perfectly random hcp solutions at those compositions. Due to the relatively small size of the generated structures, they can be used to calculate the properties of random hcp alloys via first-principles methods. The structures are relaxed in order to find their lowest energy configurations at each composition. In some cases, it was found that full relaxation resulted in complete loss of their parental symmetry as hcp so geometry optimizations in which no local relaxations are allowed were also performed. In general, the first-principles results for the seven binary systems ͑Cd-Mg, Mg-Zr, Al-Mg, Mo-Ru, Hf-Ti, Hf-Zr, and Ti-Zr͒ show good agreement with both formation enthalpy and lattice parameters measurements from experiments. It is concluded that the SQS's presented in this work can be widely used to study the behavior of random hcp solutions.

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Section: Introductionmentioning

confidence: 99%

Thermodynamic properties of binary hcp solution phases from special quasirandom structures

et al. 2006

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“…Discussions of the strategies for coupling first-principles and CALPHAD methods, along with some illustrative examples, can be found in Refs. [63,[94][95][96][97][98].…”

Section: Application To Compositionally Disordered Materialsmentioning

confidence: 99%

Atomistic modeling of interfaces and their impact on microstructure and properties

2010

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Atomic-level modeling of materials provides fundamental insights into phase stability, structure and properties of crystalline defects, and to physical mechanisms of many processes ranging from atomic diffusion to interface migration. This knowledge often serves as a guide for the development of mesoscopic and macroscopic continuum models, with input parameters provided by atomistic models. This paper gives an overview of the most recent developments in the area of atomistic modeling with emphasis on interfaces and their impact on microstructure and properties of materials. Modern computer simulation methodologies are discussed and illustrated by several applications related to thermodynamic, kinetic and mechanical properties of materials. Existing challenges and future research directions in this field are outlined.

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“…A multiscale approach [18] was applied to model Al 2 Cu-θ phase, and was validated by the comparison with the morphology and microstructural experimental data. It was followed by several ab initio studies of Wolverton et al [19][20][21][22][23] and Zhou et al [24]. Wolverton et al [20] and Wang et al [25] showed that copper monolayers were more stable than bilayers.…”

Section: Introductionmentioning

confidence: 99%

DFT Modelling of Cu Segregation in Al-Cu Alloys Covered by an Ultrathin Oxide Film and Possible Links with Passivity

Cornette

Costa

Marcus

2017

Metals

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Abstract:We modelled with Density Functional Theory (DFT) an Al-Cu alloy covered with a passive film, with several Cu concentrations (from the limit of the isolated atom to the monolayer) at the interface with the oxide, as well as Guinier-Preston 1 (GP1) zones. At low (respectively high) concentration, Cu segregates in the first (respectively second) metal layer underneath the passive film. The Cu monolayer is the most stable configuration (−0.37 eV/Cu atom). GP1 zones were modelled, with a three-copper atom cluster in the alloy. The GP1 zone is slightly favoured with respect to the Cu monolayer under the oxide film. A low (respectively high) Cu concentration induces an electronic workfunction increase (respectively decrease) by 0.3 eV (respectively −0.4 to −0.6 eV) as compared to pure Al. In contrast, without oxide, Cu segregation at the Al surface induces no workfunction change at low concentration and an increase of 0.3 eV of the workfunction at high concentration. Thus, the presence of oxide modifies the expected tendency of workfunction increase by adding a more noble metal. For the studied models, no spontaneous electron transfer occurs to the O 2 molecule.

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Incorporating first-principles energetics in computational thermodynamics approaches

Cited by 92 publications

References 27 publications

Thermodynamic properties of binary hcp solution phases from special quasirandom structures

Thermodynamic properties of binary hcp solution phases from special quasirandom structures

Atomistic modeling of interfaces and their impact on microstructure and properties

DFT Modelling of Cu Segregation in Al-Cu Alloys Covered by an Ultrathin Oxide Film and Possible Links with Passivity

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