Weak bonding of alumina coatings on Ni(111)

Jarvis, Emily; Christensen, Asbjørn; Carter, Emily A.

doi:10.1016/s0039-6028(01)01071-8

Cited by 51 publications

(36 citation statements)

References 98 publications

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“…In other work, 12 we have determined that Al 2 O 3 -Ni interfaces are also quite weakly adhered, suggesting spallation occurs at any interface in the TBC where Al 2 O 3 is present.…”

Section: Discussionmentioning

confidence: 53%

See 1 more Smart Citation

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−
Christensen
¹
,
Carter
²

2000
Phys. Rev. B
66
3
29
1
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“…In other work, 12 we have determined that Al 2 O 3 -Ni interfaces are also quite weakly adhered, suggesting spallation occurs at any interface in the TBC where Al 2 O 3 is present.…”

Section: Discussionmentioning

confidence: 53%

“…We have also examined the Al 2 O 3 /Ni interaction, 12 where we learn that Al 2 O 3 may be responsible for the spallation that occurs. We have also studied the ZrO 2 /Ni(111) interface 13 to understand on an atomistic level why the bond coat is necessary at all between the TBC and a Ni-rich superalloy.…”

Section: Introductionmentioning

confidence: 99%

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−
Christensen
¹
,
Carter
²

2000
Phys. Rev. B
66
3
29
1
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“…When cleaved, the ͑0001͒ surface of the brittle ceramic, ␣-Al 2 O 3 , undergoes severe inward relaxation of the Al ions by ϳ0.7 Å relative to the bulk termination. 21 The exposed ͑100͒ semiconductor Si surface also relaxes inward by 2% relative to the bulk termination, but more importantly, the surface undergoes a 2ϫ1 reconstruction resulting in rows of dimers. 22 We use 3D periodic generalized gradient approximation ͑PW91͒ DFT calculations implemented within the VASP code.…”

Section: ͑7͒mentioning

confidence: 99%

Universal binding-energy relation for crystals that accounts for surface relaxation

2004

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We present a universal relation for crack surface cohesion including surface relaxation. Specifically, we analyze how N atomic planes respond to an opening displacement at its boundary, producing structurally relaxed surfaces. Via density-functional theory, we verify universality for metals ͑Al͒, ceramics (␣-Al 2 O 3 ), and semiconductors ͑Si͒. When the energy and opening displacement are scaled appropriately with respect to N, the uniaxial elastic constant, the relaxed surface energy, and the equilibrium interlayer spacing, all energydisplacement curves collapse onto a single universal curve. DOI: 10.1103/PhysRevB.69.172104 PACS number͑s͒: 61.50.Lt, 68.35.Ϫp, 71.15.Mb Macroscopic cohesive theories of fracture often involve empirical postulates on the shape and form of the cohesive law.1-3 While first principles simulations might be preferable, the typical size of engineering finite element models prohibits their direct application. In order to obtain converged finite element results, the cohesive zone size must be resolved by the mesh; for brittle materials, the cohesive zone size is atomistic, making the calculation prohibitively expensive.4 Nanometer scale quantum mechanical calculations have provided insight into cracking at the atomic level, 5-8 but their extrapolation to the macroscopic scale is fraught with difficulty. Indeed, orders-of-magnitude mismatch exist between atomistic predictions of cohesive strengths and critical opening displacements 9-11 and measurements of tensile strength in brittle materials obtained from spallation tests, 12 the latter of which are often employed in engineering simulations. The widely used universal binding energy relation ͑UBER͒ of Rose et al.13 describes cohesion between rigid surfaces based on atomic scale calculations, but application of the UBER to crack propagation simulations is hampered by its inability to capture the shape and absolute energies of cohesive laws for structurally relaxed surfaces.6,14 -16 Here, we address these difficulties by deriving a coarse-grained cohesive energy relation that accounts for structural relaxation of surfaces and exhibits a material-independent universal form.Nguyen and Ortiz recently suggested rescaling interlayer potentials to yield macroscopic cohesive laws. 17 Here we extend their work to account for surface relaxation and reconstruction. Specifically, we consider a perfect crystal acted upon by tensile stresses normal to a cleavage plane. The length scales under consideration range from mesoscopic ͑the dislocation free zone of a metal 18 ͒ to possibly macroscopic ͑brittle materials͒; we conservatively denote both scales as mesoscopic. We assume that atomic layers remain planar after deformation, so that the relative displacement of crystallographic layer i can be described by ␦ i ͑the interlayer spacing minus the equilibrium interlayer spacing, d͒ and that the crystal is periodic with a unit cell containing N atomic layers. We express the total energy per unit area of cleavage plane asis the local energy per layer of a ...

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“…[1][2][3] A second aspect of the research on metal oxide interface, this is the growth of oxides on metals, is mostly relevant to the formation of anticorrosion protections or thermal and electric insulators. 4 However, the chemical properties of these "reverse" catalysts, have also attracted significant attention. 5 The interest of the oxide on metal systems goes even further since a large number of oxides are insulators and, in order to explode the powerful ultra-high vacuum techniques, it is needed to prepare them as ultra thin films on conductive supports, i.e.…”

Section: Introductionmentioning

confidence: 99%

MgO∕Ag(001)interface structure and STM images from first principles

López

Valeri²

2004

Phys. Rev. B

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The interface of MgO / Ag͑001͒ has been studied with density functional theory applied to slabs. We have found that regular MgO films show a small adhesion to the silver substrate, the binding can be increased in off-stoichiometric regimes, either by the presence of O vacancies at the oxide film or by a small excess of O atoms at the interface between the ceramic to the metal. By means of theoretical methods, the scanning tunneling microscopy signatures of these films is also analyzed in some detail. For defect free deposits containing 1 or 2 ML and at low voltages, tunnelling takes place from the surface Ag substrate, and at large positive voltages Mg atoms are imaged. If defects, oxygen vacancies, are present on the surface of the oxide they introduce much easier channels for tunnelling resulting in big protrusions and controlling the shape of the image, the extra O stored at the interface can also be detected for very thin films.

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Weak bonding of alumina coatings on Ni(111)

Cited by 51 publications

References 98 publications

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−
Christensen
¹
,
Carter
²

2000
Phys. Rev. B
66
3
29
1
View full text Add to dashboard Cite

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−
Christensen
¹
,
Carter
²

2000
Phys. Rev. B
66
3
29
1
View full text Add to dashboard Cite

Universal binding-energy relation for crystals that accounts for surface relaxation

MgO∕Ag(001)interface structure and STM images from first principles

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Weak bonding of alumina coatings on Ni(111)

Cited by 51 publications

References 98 publications

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−Christensen1, Carter2 2000Phys. Rev. B663291View full textAdd to dashboardCite

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−Christensen1, Carter2 2000Phys. Rev. B663291View full textAdd to dashboardCite

Universal binding-energy relation for crystals that accounts for surface relaxation

MgO∕Ag(001)interface structure and STM images from first principles

Contact Info

Product

Resources

About

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−
Christensen
¹
,
Carter
²

2000
Phys. Rev. B
66
3
29
1
View full text Add to dashboard Cite

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−
Christensen
¹
,
Carter
²

2000
Phys. Rev. B
66
3
29
1
View full text Add to dashboard Cite