Composition of the (110) surface of the Fe–Ni 34 at.% alloy: a study by low-energy ion scattering

Atrei, A.; Bardi, Ugo; Rovida, G.; Blashchuk, A. G.; Mishchuk, O. N.; Vasylyev, M. O.

doi:10.1016/s0039-6028(01)00947-5

Cited by 11 publications

(9 citation statements)

References 19 publications

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“…It is well known that the catalytic performance of a bimetallic alloy is closely related to the surface composition that may substantially differ from that in its bulk. Many experimental and theoretical studies have been devoted to understanding the composition and structure of alloy surfaces and electronic properties under vacuum conditions. However, the preparation of nickel‐based electrodes usually takes place in the reactive environment with various adsorbates , and in practical applications the alloy catalysts cannot avoid interacting with reactive adsorbates.…”

Section: Introductionmentioning

confidence: 99%

First‐principles study of surface segregation in bimetallic Ni₃M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen

Zhang

Xiao

et al. 2017

Physica Status Solidi (b)

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Segregation at metal alloy surfaces has an important impact on their catalytic and chemical properties. We have performed density‐functional theory calculations to investigate the surface segregation behaviors of Ni3M (M = Mo, Co, Fe) alloys in the presence of chemisorbed atomic oxygen. The calculated results show that the segregation trend at a Ni3M(111) surface can be substantially modified by reactive gaseous environments. At an oxygen coverage of 1/4 ML, both the Ni‐segregated and M‐segregated surfaces are still less stable than the nonsegregated one for Ni3Fe alloy, while an M‐segregated surface is more stable than the nonsegregated one for Ni3M (M = Mo, Co) alloys. Furthermore, the analysis of oxygen adsorption trends and surface electronic structures explains that the surface segregation trend is directly correlated to the surface–adsorbate binding strength. The present study provides valuable insight for exploring practical applications of Ni‐based alloys as hydrogen‐evolution electrodes.

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Section: Introductionmentioning

confidence: 99%

First‐principles study of surface segregation in bimetallic Ni₃M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen

Zhang

Xiao

et al. 2017

Physica Status Solidi (b)

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“…In Fe 3 Ni, only a limited surface segregation of Ni has been reported due to a magnetic phase transition with a significant temperature dependence. 61,66 In addition, no significant segregation was observed on a clean Ni 3 Al(111) surface. 67 However, experimental investigation of surface composition is not straightforward since surface properties can be easily affected by even low concentrations of oxygen and sulfur.…”

Section: Resultsmentioning

confidence: 98%

“…The compositional changes induced by the segregation at the surface play an important role in determining the properties of alloy surface and grain boundary such as corrosion, oxidation, and embrittlement. Several studies have been carried out on Fe/Al/Ni binary alloys. − For example, high-temperature sputtering and annealing studies on FeAl surfaces have reported the formation of an Al-segregation layer near the surface. − For Fe/Ni alloys, however, no large segregation was observed due to similar size and surface energy. In Fe 3 Ni, only a limited surface segregation of Ni has been reported due to a magnetic phase transition with a significant temperature dependence. , In addition, no significant segregation was observed on a clean Ni 3 Al(111) surface .…”

Section: Resultsmentioning

confidence: 99%

“…% at the topmost surface layer. 61 Another experiment of Fe 3 Ni(110) surface reported that, due to the magnetic phase transition, the Fe concentration on the surface decreased from roughly 76% to 62% in the temperature range 560−650 K and did not change beyond the temperature range. 62 In addition, in the study of FeAl in various surface orientations using Auger electron spectroscopy (AES), Al segregation was observed in alloy multilayers.…”

Section: Resultsmentioning

confidence: 99%

“…Several studies have been carried out on Fe/Al/Ni binary alloys. − For example, high-temperature sputtering and annealing studies on FeAl surfaces have reported the formation of an Al-segregation layer near the surface. − For Fe/Ni alloys, however, no large segregation was observed due to similar size and surface energy. In Fe 3 Ni, only a limited surface segregation of Ni has been reported due to a magnetic phase transition with a significant temperature dependence. , In addition, no significant segregation was observed on a clean Ni 3 Al(111) surface . However, experimental investigation of surface composition is not straightforward since surface properties can be easily affected by even low concentrations of oxygen and sulfur.…”

Section: Resultsmentioning

confidence: 99%

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Development and Validation of a ReaxFF Reactive Force Field for Fe/Al/Ni Alloys: Molecular Dynamics Study of Elastic Constants, Diffusion, and Segregation

et al. 2012

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We have developed a ReaxFF force field for Fe/Al/Ni binary alloys based on quantum mechanical (QM) calculations. In addition to the various bulk phases of the binary alloys, the (100), (110) and (111) surface energies and adatom binding energies were included in the training set for the force field parametrization of the Fe/Al/Ni binary alloys. To validate these optimized force fields, we studied (i) elastic constants of the binary alloys at finite temperatures, (ii) diffusivity of alloy components in Al/Ni alloy, and (iii) segregation on the binary alloy surfaces. First, we calculated linear elastic constants of FeAl, FeNi(3), and Ni(3)Al in the temperature range 300 to 1100 K. The temperature dependences of the elastic constants of these three alloys, showing a decrease in C(11), C(12), and C(44) as temperature increases, were in good agreement with the experimental results. We also performed ReaxFF molecular dynamics (MD) simulations for Al or Ni diffusion in the system modeled as Al/Ni mixed layers with the linear composition gradients. At 1000 K, Al diffusivity at the pure Al end was 2 orders of magnitude larger than that in the Al trace layers, probably explaining the nature of different diffusion behavior between molten metals and alloys. However, the diffusivity of Ni at the pure Ni end was only slightly larger than that in the Ni trace layers at the system temperature much lower than the melting temperature of Ni. Third, we investigated the surface segregation in L1(2)-Fe(3)Al, Fe(3)Ni, and Ni(3)Al clusters at high temperature (2500 K). From the analysis of composition distribution of the alloy components from the bulk to the surface layer, it was found that the degree of segregation depended on the chemical composition of the alloy. Al surface segregation occurred most strongly in Fe(3)Al, whereas it occurred most weakly in Ni(3)Al. These results may support the segregation mechanism that surface segregation results from the interplay between the energetic stability of the ordered bulk phase and the surface reconstruction. In addition, the surface segregation induced the depletion layers of segregating metal species (Al in Fe(3)Al and Ni(3)Al, and Ni in Fe(3)Ni) next to the segregation layers. These simulation results qualitatively agreed with early experimental observations of segregation in Fe/Al/Ni binary alloys.

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3.5 Surface segregation of atomic species

Viefhaus¹,

Grabke²,

Uebing³

Adsorbed Layers on Surfaces

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Composition of the (110) surface of the Fe–Ni 34 at.% alloy: a study by low-energy ion scattering

Cited by 11 publications

References 19 publications

First‐principles study of surface segregation in bimetallic Ni₃M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen

First‐principles study of surface segregation in bimetallic Ni₃M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen

Development and Validation of a ReaxFF Reactive Force Field for Fe/Al/Ni Alloys: Molecular Dynamics Study of Elastic Constants, Diffusion, and Segregation

3.5 Surface segregation of atomic species

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Composition of the (110) surface of the Fe–Ni 34 at.% alloy: a study by low-energy ion scattering

Cited by 11 publications

References 19 publications

First‐principles study of surface segregation in bimetallic Ni3M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen

First‐principles study of surface segregation in bimetallic Ni3M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen

Development and Validation of a ReaxFF Reactive Force Field for Fe/Al/Ni Alloys: Molecular Dynamics Study of Elastic Constants, Diffusion, and Segregation

3.5 Surface segregation of atomic species

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Product

Resources

About

First‐principles study of surface segregation in bimetallic Ni₃M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen

First‐principles study of surface segregation in bimetallic Ni₃M (M = Mo, Co, Fe) alloys with chemisorbed atomic oxygen