Structure and stability of Fe4C bulk and surfaces: A density functional theory study

Deng, Chun-Mei; Huo, Chun‐Fang; Bao, Lili; Shi, Xue-Rong; Li, Yongwang; Wang, Jianguo; Jiao, Haijun

doi:10.1016/j.cplett.2007.09.055

Cited by 35 publications

(27 citation statements)

References 20 publications

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“…The calculated unrelaxed and relaxed surface free energies γ un and γ re (J m −2 ), the unrelaxed and relaxed topest bond length d C-C/C-B/B-B (Å), and the surface relaxation degree f (%) of BC 5 The corresponding surface relaxation degree is about 40% suggesting the relaxation of these surfaces is strong. The similar result is found in our previous studies where Fe 4 C surfaces yielded the largest relaxation degree of 39.0% [36]. As shown in tables 1, 2, and figure 2, the surface bonds contract compared with the bulk ones, resulting from the reduced coordination number of the surface atoms.…”

Section: Surface Structuresupporting

confidence: 90%

First-principles study of the surface structure and stability of BC₅

Cheng

Deng

et al. 2020

Mater. Res. Express

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BC 5 with both superhard and superconducting properties is expected to have important applications in many fields. In this work, the low-index surface structures and properties of BC 5 have been identified by first-principles calculations. The surface stability decreased in the order of (011)>(010)>(101)>(100)>(110)>(111)>(001). The (011), (101), and (110) surfaces exhibit the strongest surface relaxation, followed by (111), and the (001) surface is the least. A DFT (density functional theory)-based Wulff construction of the equilibrium shape of BC 5 shows that the surface with the largest exposure area is (011), followed by the (101) and (001) surfaces. Electronic analyses show that Pmma phase BC 5 and all considered low-index surfaces exhibit metallic character where the surfaces are even stronger. Larger charge redistribution in the low-index surfaces is found compared with the bulk case.

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Section: Surface Structuresupporting

confidence: 90%

First-principles study of the surface structure and stability of BC₅

Cheng

Deng

et al. 2020

Mater. Res. Express

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“…Fe 4 C has two allotropic forms. 3,31,32 The observed form is isostructural with ␥Ј-Fe 4 N ͑JCPDS file no. 6-0627͒: primitive There is an ambiguity in the determination of metallic iron because the ␣-Fe strongest reflection ͑110͒ at 44.67°and Fe 3 C strong reflection ͑220͒ at 44.59°almost overlap.…”

Section: Elemental Analysis Of the Films-tablementioning

confidence: 92%

“…cubic lattice, with a = 3.790 Å for Fe 4 N33 and a = 3.678 Å for Fe 4 C 3,31. There is no recorded X-ray diffraction ͑XRD͒ pattern for Fe 4 C in the JCPDS database.…”

mentioning

confidence: 99%

Chemical Vapor Deposition of Iron, Iron Carbides, and Iron Nitride Films from Amidinate Precursors

Krisyuk

Gleizes

Aloui

et al. 2010

J. Electrochem. Soc.

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“…The authors of [8] estimated the ratio of the carbon diffusion coefficient in equilibrium and in carbon-supersaturated lattice at room temperature of as high as 10 6 . Extended carbon clusters and transient carbides were directly observed [14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 94%

Extremely slow carbon diffusion in carbon-supersaturated surface of ferrite

CERMAK¹,

Král²

2021

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Carbon diffusion was studied in carbon-supersaturated surface layer of commercial ferrite-martensite Cr-Mo steel P91 and in two model ferrite materials: in pure α-Fe, and in ferrite Fe-Cr alloy. The carbon surface layer, the thickness of which was about 40 nm, was physical-vapor-deposited and isothermal diffusion anneals were carried out at selected temperatures between 573 K and 1073 K. The depth profiles of carbon were measured by SIMS. It was found that the carbon diffusion proceeded much more slowly in carbon-supersaturated surfaces than in matrices with equilibrium carbon concentration. The carbon diffusion coefficients obtained, D, were close to literature values reported for C diffusion in carbide phase. Measured values of D in pure α-Fe, α-Fe-Cr and P91 steel above 773 K were identical. However, significantly higher values of D were measured in P91 below the temperature of 773 K, which was ascribed to different mobility of substitution elements.

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Structure and stability of Fe4C bulk and surfaces: A density functional theory study

Cited by 35 publications

References 20 publications

First-principles study of the surface structure and stability of BC₅

First-principles study of the surface structure and stability of BC₅

Chemical Vapor Deposition of Iron, Iron Carbides, and Iron Nitride Films from Amidinate Precursors

Extremely slow carbon diffusion in carbon-supersaturated surface of ferrite

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Structure and stability of Fe4C bulk and surfaces: A density functional theory study

Cited by 35 publications

References 20 publications

First-principles study of the surface structure and stability of BC5

First-principles study of the surface structure and stability of BC5

Chemical Vapor Deposition of Iron, Iron Carbides, and Iron Nitride Films from Amidinate Precursors

Extremely slow carbon diffusion in carbon-supersaturated surface of ferrite

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Product

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First-principles study of the surface structure and stability of BC₅

First-principles study of the surface structure and stability of BC₅