Misfit dislocation generation in epitaxial layers

Merwe, Jan H. van der

doi:10.1080/10408439108243751

Cited by 110 publications

(50 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recently, there has been much interest [1][2][3][4][5][6][7][8][9][10][11][12][13][14] in growth of epitaxial metal films and superlattices due to their unusual physical properties. The quality and structure of these systems is of paramount importance for applications.…”

Section: Introductionmentioning

confidence: 99%

Effects of anharmonic strain on the phase stability of epitaxial films and superlattices: Applications to noble metals

1998

View full text Add to dashboard Cite

Epitaxial strain energies of epitaxial films and bulk superlattices are studied via first-principles total energy calculations using the local-density approximation. Anharmonic effects due to large lattice mismatch, beyond the reach of the harmonic elasticity theory, are found to be very important in Cu/Au (lattice mismatch 12%), Cu/Ag (12%) and Ni/Au (15%). We find that 001 is the elastically soft direction for biaxial expansion of Cu and Ni, but it is 201 for large biaxial compression of Cu, Ag, and Au. The stability of superlattices is discussed in terms of the coherency strain and interfacial energies. We find that in phase-separating systems such as Cu-Ag the superlattice formation energies decrease with superlattice period, and the interfacial energy is positive. Superlattices are formed easiest on (001) and hardest on (111) substrates. For ordering systems, such as Cu-Au and Ag-Au, the formation energy of superlattices increases with period, and interfacial energies are negative. These superlattices are formed easiest on (001) or (110) and hardest on (111) substrates. For NiAu we find a hybrid behavior: superlattices along 111 and 001 behave like in phase-separating systems, while for 110 they behave like in ordering systems. Finally, recent experimental results on epitaxial stabilization of disordered Ni-Au and Cu-Ag alloys, immiscible in the bulk form, are explained in terms of destabilization of the phase separated state due to lattice mismatch between the substrate and constituents.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of anharmonic strain on the phase stability of epitaxial films and superlattices: Applications to noble metals

1998

View full text Add to dashboard Cite

show abstract

“…The difference discussed here between real and model systems is standard in the theory of defects in heteroepitaxial systems. For example, the formation of MDs at film/substrate boundaries in conventional heteroepitaxial systems depends on many factors (relief of the film free surface, distribution of pre-existent dislocations in a substrate, etc) which are not taken into account in theoretical models that commonly deal with the averaged and technologically controlled characteristics (the mean film thickness and misfit parameter) of heteroepitaxial systems; see, e.g., the reviews [7,9,21]. Although the theoretical model suggested in this paper does not take into consideration the disorder in spatial arrangement of deformation-induced sub-boundaries, its results allow one to estimate in the first approximation the influence of pre-deformation of substrates on the formation of MDs in multilayered films deposited onto the deformed substrates.…”

Section: Discussion and Concluding Remarksmentioning

confidence: 99%

“…In particular, all the derivations of this paper rely on isotropic elasticity, whereas real systems are in many cases elastically anisotropic. The assumption of isotropic elasticity is conventional in the theory of MDs in heteroepitaxial systems; see, e.g., the reviews [7,9,21]. A theoretical description of defects in heteroepitaxial systems which accounts for anisotropic effects (e.g., [18]) gives rise to inessential (about 10%) corrections of isotropic-theory-based estimates of the critical thickness.…”

Section: Formation Of Disclinations In Plastically Deformed Substratesmentioning

confidence: 99%

Misfit dislocations in multilayered films on disclinated substrates

Ovid’ko

Sheĭnerman

2001

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

A theoretical model which describes the generation of misfit dislocations in multilayered films deposited onto plastically deformed substrates with disclinations (defects of rotational type) is suggested. In the framework of the model, the ranges of the parameters (disclination strength, misfit parameters, layer thicknesses, characteristics of disclination arrangement) of a multilayered film/substrate composite for which the generation of misfit dislocations is energetically favourable are calculated. The specific features of the generation of misfit dislocations in multilayered films on disclinated substrates are discussed in relation to a technologically interesting possibility for exploiting plastically deformed substrates.

show abstract

“…The dilatation misfit at crystal-glass interfaces is similar to that at conventional crystal-crystal interfaces. Therefore, it is effectively described in terms of the dilatation misfit parameter and associated dilatation misfit stresses and misfit dislocations; see, e.g., reviews [21][22][23]. Since a description of the dilatation misfit is a standard procedure, here and in the following we will focus our consideration on a description of only the orientational misfit and associated misfit disclinations at crystal-glass interfaces.…”

Section: Structural Geometry Of Crystal-glass Interfaces Misfit Discmentioning

confidence: 99%

Nanoscale defect structures at crystal–glass interfaces

Bobylev

Ovid’ko

Романов

et al. 2005

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

A theoretical model of two-phase crystal-glass composite materials is suggested which is based on the disclination description of glassy structures. In the framework of the model, the crystal-glass composite is described as a solid that contains nanoscale configurations of disclination-dislocation loops in the glassy phase. Specific defects at the crystal-glass interface are defined and theoretically described which are misfit disclinations generated as extensions of parent wedge disclinations present in the glassy phase. In doing so, the defect ensemble in the crystal-glass composite is characterized by nanoscale inhomogeneities in both the defect density and stress in the vicinity of the crystal-glass interface. The formulae for the stress fields created by ensembles of the disclination-dislocation loops in crystal-glass composites are derived. With these formulae, the energy of the crystal-glass interface is estimated.

show abstract

Misfit dislocation generation in epitaxial layers

Cited by 110 publications

References 69 publications

Effects of anharmonic strain on the phase stability of epitaxial films and superlattices: Applications to noble metals

Effects of anharmonic strain on the phase stability of epitaxial films and superlattices: Applications to noble metals

Misfit dislocations in multilayered films on disclinated substrates

Nanoscale defect structures at crystal–glass interfaces

Contact Info

Product

Resources

About