First-principles calculations of the structural and thermodynamic properties of bcc, fcc and hcp solid solutions in the Al–TM (TM=Ti, Zr and Hf) systems: A comparison of cluster expansion and supercell methods

Ghosh, Gautam; Walle, Axel van de; Asta, Mark

doi:10.1016/j.actamat.2008.03.006

Cited by 142 publications

(86 citation statements)

References 85 publications

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“…2͒ is relatively fast, with pair interactions of less than the fifthnearest-neighbor sufficient to obtain converged CEs. This contrasts with studies of metallic alloys, e.g., Al-TM ͑TM = Ti, Zr, and Hf͒ where interactions beyond the 10th neighbor shell are required, 40 and a large number of many-body ͑triplet and four-body͒ clusters need to be included. As expected, the ECIs exhibit a general trend of decreasing in amplitude with distance ͑Fig.…”

Section: Introductionmentioning

confidence: 89%

First-principles phase diagram calculations for the HfC–TiC, ZrC–TiC, and HfC–ZrC solid solutions

et al. 2009

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We report first-principles phase diagram calculations for the binary systems HfC-TiC, TiC-ZrC, and HfCZrC. Formation energies for superstructures of various bulk compositions were computed with a plane-wave pseudopotential method. They in turn were used as a basis for fitting cluster expansion Hamiltonians, both with and without approximations for excess vibrational free energies. Significant miscibility gaps are predicted for the systems TiC-ZrC and HfC-TiC, with consolute temperatures in excess of 2000 K. The HfC-ZrC system is predicted to be completely miscibile down to 185 K. Reductions in consolute temperature due to excess vibrational free energy are estimated to be ϳ7%, ϳ20%, and ϳ0%, for HfC-TiC, TiC-ZrC, and HfC-ZrC, respectively. Predicted miscibility gaps are symmetric for HfC-ZrC, almost symmetric for HfC-TiC and asymmetric for TiC-ZrC.

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Section: Introductionmentioning

confidence: 89%

First-principles phase diagram calculations for the HfC–TiC, ZrC–TiC, and HfC–ZrC solid solutions

et al. 2009

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“…For solid solutions, in systems where short-range order can be neglected, computationally less demanding approaches for calculating the energetics of random alloys involve the use of the CPA [67,68,70] or special quasi-random structures [74][75][76][77][78], which are ordered structures designed to have correlation functions approximating those of a disordered alloy.…”

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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“…Modern computational resources have made DFT viable as a high-throughput materials design technique [2][3][4] , whereby the existence, stability, and properties of periodic crystalline phases are predicted entirely from first principles. These approaches are especially attractive for predicting the properties of systems that are otherwise too expensive or difficult to study experimentally, such as alloys containing Ru 5 , Tc 6 , and Pt 7 , among others [8][9][10][11] .…”

Section: Introductionmentioning

confidence: 99%

Testing predictions from density functional theory at finite temperatures:β2-like ground states in Co-Pt

Decolvenaere¹,

Gordon²,

Ven³

2015

Phys. Rev. B

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We perform a critical assessment of the accuracy of DFT-based methods in predicting stable phases within the Co-Pt binary alloy. Statistical mechanical analysis applied to zero kelvin DFT predictions yields finite-temperature results that can be directly compared with experimental measurements. The predicted temperature-composition phase diagram is qualitatively incompatible with experimental observations, indicating that the predicted stability of long-period superstructures as ground states in the Co-Pt binary is incorrect. We also show that recently suggested methods to better align DFT and experiment via the hybrid functional HSE06 are unable to resolve the discrepancies in this system. Our results indicate a need for better verification of DFT based phase stability predictions, and highlight fundamental flaws in the ability of DFT to treat late 3d -5d binary alloys.

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First-principles calculations of the structural and thermodynamic properties of bcc, fcc and hcp solid solutions in the Al–TM (TM=Ti, Zr and Hf) systems: A comparison of cluster expansion and supercell methods

Cited by 142 publications

References 85 publications

First-principles phase diagram calculations for the HfC–TiC, ZrC–TiC, and HfC–ZrC solid solutions

First-principles phase diagram calculations for the HfC–TiC, ZrC–TiC, and HfC–ZrC solid solutions

Atomistic modeling of interfaces and their impact on microstructure and properties

Testing predictions from density functional theory at finite temperatures:β2-like ground states in Co-Pt

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