Step-Driven Surface Segregation and Ordering During Si-Ge MBE Growth

1992 ◽  
Vol 263 ◽  
Author(s):  
D. E. Jesson ◽  
S. J. Pennycook ◽  
J.-M. Baribeau ◽  
D. C. Houghton
Keyword(s):  
Surface Segregation ◽  
Ordered Structure ◽  
Mbe Growth ◽  
Vertical Segregation ◽  
Z Contrast ◽  
Lateral Segregation ◽  
Phase Variants ◽  
Step Edges

ABSTRACTAn important role of type SB step edges in determining the as-grown microstructure of Si-Ge superlattices and alloys is implicated from direct Z-contrast images of as-grown structures. A variety of different ordered phase variants can arise at each Si on Ge interface as a result of vertical segregation during superlattice growth. A new monoclinic-ordered structure is predicted to arise as a result of lateral segregation during alloy growth.

Direct Imaging of Ordering in Si-Ge Alloys, Ultrathin Superlattices, and Buried Ge Layers

1991 ◽  
Vol 220 ◽  
Author(s):  
D. E. Jesson ◽  
S. J. Pennycook ◽  
J. -M. Baribeau
Keyword(s):  
Long Range ◽  
Imaging Studies ◽  
Contrast Imaging ◽  
Direct Imaging ◽  
Mbe Growth ◽  
Nonequilibrium Growth ◽  
Pump Mechanism ◽  
Z Contrast ◽  
Lateral Segregation

ABSTRACTWe review recent Z-contrast imaging studies of Si-Ge ultrathin superlattices, alloys, and buried Ge layers. It is found that whenever Si is deposited onto a Ge (2 × 1) surface, Ge is pumped into the growing Si layer, and this is accompanied by interfacial ordering. This is explained by a novel Ge atom pump mechanism which occurs during MBE growth. Codeposition and alloy growth results in long range (111) ordering as a consequence of lateral segregation during nonequilibrium growth.

scholarly journals Role of step edges on the structure formation of α-6T on Ag(441)

2018 ◽  
Vol 667 ◽  
pp. 17-24 ◽  
Author(s):  
Thorsten Wagner ◽  
Daniel Roman Fritz ◽  
Zdena Rudolfová ◽  
Peter Zeppenfeld
Keyword(s):  
Structure Formation ◽  
Step Edges

Oxidation of Au on vicinal W(110): Role of step edges and facets

2007 ◽  
Vol 75 (20) ◽  
Author(s):  
A. Varykhalov ◽  
O. Rader ◽  
V. K. Adamchuk ◽  
W. Gudat ◽  
B. E. Koel ◽  
...  
Keyword(s):  
Step Edges

Role of Ge surface segregation in Si/Ge interfacial ordering: Interface formation on a monohydride surface

1995 ◽  
Vol 51 (20) ◽  
pp. 14786-14789 ◽  
Author(s):  
Nobuyuki Ikarashi ◽  
Atsushi Oshiyama ◽  
Akira Sakai ◽  
Toru Tatsumi
Keyword(s):  
Surface Segregation ◽  
Interface Formation

Slip, twinning, and fracture at a grain boundary in the L12 ordered structure—AΣ = 9 tilt boundary

1988 ◽  
Vol 3 (5) ◽  
pp. 848-855 ◽  
Author(s):  
M. H. Yoo ◽  
A. H. King
Keyword(s):  
Intergranular Fracture ◽  
Local Stress ◽  
Boundary Region ◽  
Anisotropic Elasticity ◽  
Tilt Boundary ◽  
Microplastic Deformation ◽  
Ordered Structure ◽  
Local Stress Concentration ◽  
Boron Segregation

The role of interaction between slip dislocations and a Σ = 9 tilt boundary in localized microplastic deformation, cleavage, or intergranular fracture in the Li2 ordered structure has been analyzed by using the anisotropic elasticity theory of dislocations and fracture. Screw superpartials cross slip easily at the boundary onto the (1$\overline 1$1) and the (001) planes at low and high temperatures, respectively. Transmission of primary slip dislocations onto the conjugate slip system occurs with a certain degree of difficulty, which is eased by localized disordering. When the transmission is impeded, cleavage fracture on the ($\overline 1$11) plane is predicted to occur, not intergranular fracture, unless a symmetric double pileup occurs simultaneously. Absorption (or emission) of superpartials occurs only when the boundary region is disordered. Slip initiation from pre-existing sources near the boundary can occur under the local stress concentration. Implications of the present result on the inherent brittleness of grain boundaries in Ni3 Al and its improvement by boron segregation are discussed.

scholarly journals Role of oxygen in Cu(1 1 0) surface restructuring in the vicinity of step edges

2014 ◽  
Vol 613 ◽  
pp. 64-69 ◽  
Author(s):  
Liang Li ◽  
Na Cai ◽  
Wissam A. Saidi ◽  
Guangwen Zhou
Keyword(s):  
Surface Restructuring ◽  
Step Edges

On the Role of Metal Step-Edges in Graphene Growth

2010 ◽  
Vol 114 (25) ◽  
pp. 11221-11227 ◽  
Author(s):  
Souheil Saadi ◽  
Frank Abild-Pedersen ◽  
Stig Helveg ◽  
Jens Sehested ◽  
Berit Hinnemann ◽  
...  
Keyword(s):  
Graphene Growth ◽  
Step Edges

The Role of Low-Energy Ion/Surface Interactions During Crystal Growth From the Vapor Phase

1986 ◽  
Vol 74 ◽  
Author(s):  
J. E. Greene ◽  
A. Rockett ◽  
J.-E. Sundgren
Keyword(s):  
Surface Segregation ◽  
Ion Irradiation ◽  
Ion Bombardment ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Low Energy ◽  
Nucleation Kinetics ◽  
Wear Resistant Coatings ◽  
Average Grain Size

AbstractLow-energy (often < 100 eV) ion bombardment during thin film deposition is commonly used in such diverse application areas as microelectronics, optical coatings. magnetic recording layers. and hard wear resistant coatings to modify the microstructure and microchemistry of films deposited by a variety of techniques (e.g. sputtering, primary ion deposition, plasma-assisted CVD, and accelerated-beam MBE). Ion irradiation has been shown to affect every phase of deposition including nucleation and growth kinetics, crystal structure and phase stability, the average grain size and degree of preferred orientation of polycrystalline films, the epitaxial temperature of single-crystal films, defect concentrations, elemental incorporation probabilities, surface segregation, and, hence, film properties. As discussed in this brief review, a detailed understanding of many of these processes is beginning to emerge. Effects such as trapping, preferential sputtering, enhanced diffusion, and collisional mixing have been used to interpret and, in some cases, model experimental results. Nevertheless, there are still large gaps in our knowledge of the role of ion bombardment on fundamental processes such as nucleation kinetics.

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