On the coincidence site lattice and DSC dislocation network model of high angle grain boundary structure

1980 ◽  
Vol 14 (1) ◽  
pp. 129-132 ◽  
Author(s):  
A.P. Sutton ◽  
V. Vitek
Keyword(s):  
Grain Boundary ◽  
Network Model ◽  
Coincidence Site Lattice ◽  
Boundary Structure ◽  
Dislocation Network ◽  
High Angle ◽  
Site Lattice ◽  
Grain Boundary Structure

Observations and implications of grain boundary dislocation networks in high-angle YBa2Cu3O7−δ grain boundaries

1990 ◽  
Vol 5 (5) ◽  
pp. 919-928 ◽  
Author(s):  
S. E. Babcock ◽  
D. C. Larbalestier
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Weak Link ◽  
Coincidence Site Lattice ◽  
Boundary Structure ◽  
High Angle ◽  
Grain Boundary Structure ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Regular Networks

Regular networks of localized grain boundary dislocations (GBDs) have been imaged by means of transmission electron microscopy in three different types of high-angle grain boundaries in YBa2Cu3O7-δ, implying that these boundaries possess ordered structures upon which a significant periodic strain field is superimposed. The occurrence of these GBD networks is shown to be consistent with the GBD/Structural Unit and Coincidence Site Lattice (CSL)/Near CSL descriptions for grain boundary structure. Thus, these dislocations appear to be intrinsic features of the boundary structure. The spacing of the observed GBDs ranged from ∼10 nm to ∼100 nm. These GBDs make the grain boundaries heterogeneous on a scale that approaches the coherence length and may contribute to their weak-link character by producing the “superconducting micro-bridge” microstructure which has been suggested on the basis of detailed electromagnetic measurements on similar samples.

The hierarchy of grain boundary structures in SiC bicrystals

1988 ◽  
Vol 46 ◽  
pp. 596-597
Author(s):  
Y. Ishida ◽  
H. Ichinose ◽  
Y. Inomata
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Lattice Theory ◽  
Coincidence Site Lattice ◽  
Boundary Structure ◽  
Geometrical Theory ◽  
Site Lattice ◽  
Atomic Structures ◽  
Grain Boundary Structure ◽  
Predictive Role

The standard geometrical theory having been developed to describe periodically ordered grain boundaries in metals, ie coincidence-site lattice theory faces a new frontier to be expanded in terms of hierarchy of atomic structures in low energy grain boundaries of polytype SiC bicrystals. The unit translation lattice of the polytype crystal is large and elongated in the direction perpendicular to the basal plane. With the elongated translation lattice, the coincidence-site lattice is generally very large. Often too large to be physically significant, although the predictive role of the coincidence-site lattice theory in specifying the orientation of periodically ordered interface was still preserved. Such periodically ordered boundaries were indeed found to occur in the present SiC bicrystals as is predicted by the geometrical theory. A dual description of the grain boundary structure in terms of hierarchy of atomic structures is shown useful in characterizing the bicrystal boundaries.High purity SiC bicrystals were produced by sublimation-deposition method by cooling the encapseled SiC slowly from 2800K.

Texture and Grain Boundary Structure Dependence of Hillock Formation in Thin Metal Films

1998 ◽  
Vol 516 ◽  
Author(s):  
Matithew M. Nowell ◽  
David P. Field
Keyword(s):  
Grain Boundary ◽  
Integrated Circuit ◽  
Downstream Processing ◽  
Metal Films ◽  
Boundary Structure ◽  
High Angle ◽  
Structure Dependence ◽  
Local Character ◽  
Grain Boundary Structure ◽  
Hillock Formation

AbstractThe development of hillocks on metal films during annealing is detrimental to downstream processing of integrated circuit structures. This work focuses upon the local character of texture and grain boundary structure near hillocks in metal films. It is apparent from the results that local grain boundary structure and texture strength are important parameters in identifying locations in the films that are preferentially susceptible to failure under given conditions. Results in aluminum and platinum films indicate that non-(111) oriented grains preferentially contain hillocks. In addition, (111) oriented grains with boundaries characterized by high angle rotations about random axes are prone to hillock formation.

TEM Study of Secondary Grain Boundary Dislocations in Near-∑13, Near-∑17 and Near-∑29 [001] Twist Boundaries in Gold

1985 ◽  
Vol 43 ◽  
pp. 244-245
Author(s):  
S.E. Babcock
Keyword(s):  
Electron Microscopy ◽  
Grain Boundary ◽  
Boundary Structure ◽  
Ordered Structure ◽  
Boundary Dislocation ◽  
High Angle ◽  
Extensive Search ◽  
Grain Boundary Structure ◽  
Transmission Electron ◽  
Twist Boundaries

In 1970, an extensive search by transmission electron microscopy (TEM) for evidence of ordered structure in high-angle [001] twist boundaries helped to establish the credibility of the DSC/CSL description of grain boundary structure. In this work, square grids of line contrast were found in boundaries for which the twist misorientation (Θ) was very near the special Σ5+ Σ13 and Σ17 Θ. The lines ran parallel to the primitive translation vectors (b(1) and b(2)) of the appropriate low-Σ DSC lattice, and their spacing correlated well with the spacing predicted by Frank's formula for dislocations with Burgers vectors b(1) and b(2). The images were interpreted as secondary grain boundary dislocation (SGBD) networks. Only for the near-Σ5 case was g•b analysis carried out to show that the line contrast was characteristic of b= 1/10 <310> type screw SGBD's.

Structure of Σ7 grain boundary in Al2O3

1994 ◽  
Vol 52 ◽  
pp. 718-719
Author(s):  
C. C. Chu ◽  
F.-R. Chen ◽  
C.-Y. Wang ◽  
L. Chang
Keyword(s):  
Grain Boundary ◽  
Atomic Structure ◽  
Coincidence Site Lattice ◽  
High Vacuum ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Cubic Symmetry ◽  
Grain Boundary Structure ◽  
Resolution Electron

In the past, extensive high resolution electron microscopy has been applied to the atomic structure of grain boundaries of cubic symmetry. In order to have a better understanding of generalization of the grain boundary theory, it could be fruiful to study grain boundary structure of non-cubic and low symmetry crystals in which case the exact CSL’s may not exist. Al2O3 has a hexagonal crystal structure ( non-cubic). In the case of hexagonal crystals, three dimensional coincidence site lattices (CSL’s) are only possible for rational values of (c/a), except for rotations about the [0001] axis. The (c/a) of α-Al2O3 is very close to a rational number (15/2) such that constrained coincidence-site lattice (CCSL) misorientations can be found. In this research, we study the atomic structure of Σ7 grain boundary. The misonentation of Σ7 is [011]/180°. The bicrystals of Σ7 were made by diffusion bonding in high temperature and high vacuum.Figs. 1 (a) and (b). show typical HRTEM images of Σ7 Al2O3 boundary recorded at the underfocus values -48 nm and -96 nm, respectively. The beam direction is parallel to a common axis [20].

Intrinsic Structure in Grain Boundaries and Boundary Mobility

1978 ◽  
Vol 36 (3) ◽  
pp. 380-391
Author(s):  
L.M. Clarebrough ◽  
C.T. Forwood
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Low Energy ◽  
Boundary Structure ◽  
Boundary Mobility ◽  
High Angle ◽  
Intrinsic Structure ◽  
Cornell University ◽  
Grain Boundary Structure ◽  
Energy Configurations

An outstanding experimental contribution to the knowledge of grain boundary structure in the 1970's is the work of Balluffi and his colleagues at Cornell University on artificially fabricated boundary interfaces in thin films of gold (e.g., Balluffi, Komem and Schober, 1972; Balluffi, Goodhew, Tan and Wagner, 1975). In particular, for high-angle boundaries they have shown that secondary grain boundary dislocations (g.b.d's.) do exist and accommodate a deviation from a low-energy misorientation corresponding to an exact C.S.L. relationship. Further, following the results of Spyridelis, Delavignette and Amelinckx (1967) they have shown that a network of g.b.d's. can act as a diffraction grating, causing extra reflections whose spacing is reciprocally related to the separation of the g.b.d's. (Balluffi, Sass and Schober, 1972). The description of high-angle grain boundaries in terms of secondary g.b.d's. accommodating a departure from an exact C.S.L. orientation is based solely on geometrical considerations, but it has been pointed out that other low-energy configurations may be preferred when account is taken of the nature of interatomic forces (Gleiter and Pumphrey, 1976; Hermann, Gleiter and Baro, 1976; Smith, Vitek and Pond, 1977).

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