Dislocations glissile

We start with dislocations and describe both glissile (conservative) and climb (nonconservative) motion in Chapter 11. The motion of vapor/crystal interfaces and liquid/crystal interfaces is taken up in Chapter 12. Finally, the complex subject of the motion of crystal/crystal interfaces is treated in Chapter 13, including both glissile and nonconservative motion. 

Crystal/crystal interfaces possess more degrees of freedom than vapor/crystal or liquid/crystal interfaces. They may also contain line defects in the form of interfacial dislocations, dislocation-ledges, and pure ledges. Therefore, the structures and motions of crystal/crystal interfaces are potentially more complex than those of vapor/crystal and liquid/crystal interfaces. Crystal/crystal interfaces experience many different types of pressures and move by a wide variety of atomic mechanisms, ranging from rapid glissile motion to slower thermally activated motion. An overview of crystal/crystal interface structure is given in Appendix B. 

Glissile Motion of Sharp Interfaces by Interfacial Dislocation Glide... 

Heterophase Interfaces. In certain cases, sharp heterophase interfaces are able to move in military fashion by the glissile motion of line defects possessing dislocation character. Interfaces of this type occur in martensitic displacive transformations, which are described in Chapter 24. The interface between the parent phase and the newly formed martensitic phase is a semicoherent interface that has no long-range stress field. The array of interfacial dislocations can move in glissile fashion and shuffle atoms across the interface. This advancing interface will transform... 

It is useful if, first of all, we consider the motion of many dislocations on one slip plane (5,11). We shall see later (Section II,C,3) that a series of dislocation loops may glide freely (i.e., w e are referring to glissile dislocations) from a particular source, so that a continual supply of dislocations moves over the slip plane in question (see Fig. 16). A pileup of... 

The dislocations expected in the M0S2 structure are formally analogous to those that can exist in graphite—see the list of four distinct kinds in Section IV,C,l,a. As before the glissile basal-plane dislocations are by far the most widely occurring (176, 177) but are of least significance in the oxidation process. About lO undissociated basal-plane dislocations occur in cleaved sections of naturally occurring molybdenite... 

Although the dissociation of a shuffle dislocation is unlikely stricto sensu, a dissociation involving shuffle dislocations was studied from a theoretical viewpoint by different authors [10-12,15]. This dissociation leads to a stacking fault between type II planes, bounded at one end by a glissile Shockley dislocation and at the... 

Growth-related defects such as Ii BSFs, which are surrounded by sessile - Shockley partial dislocations, are probably responsible for accommodation of azimuthal rotation of adjacent GaN grains and compensation of lattice mismatch in the [0001] direction between the substrate and the GaN layer. The appearance of BSFs surrounded by glissile Shockley partial dislocations is probably a result of local stress relaxation on the c plane from lattice mismatch and different thermal expansion coefficients between the GaN and the AlN/4H-SiC. If there is no effective way to neutralize stress, then formation of cracks is expected. Such cracks are visible in cross-section samples imaged by TEM. These cracks appear always at some distance from the AlN buffer layer, usually about 100 nm. Once formed, they continue to propagate to the sample surface. The measured average distance between cracks was about 2 p,m. 

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