Chemically Induced Step Edge Diffusion Barriers: Dendritic Growth in 2D Alloys

1996 ◽  
Vol 76 (25) ◽  
pp. 4757-4760 ◽  
Author(s):  
R. Q. Hwang
Keyword(s):  
Dendritic Growth ◽  
Diffusion Barriers ◽  
Step Edge ◽  
Chemically Induced

The Ehrlich-Schwoebel Effect for Vacancies: Low-Index Faces of Silver

2000 ◽  
Vol 648 ◽  
Author(s):  
Michael I. Haftel
Keyword(s):  
Diffusion Barrier ◽  
Activation Barrier ◽  
Diffusion Barriers ◽  
Step Edge ◽  
Embedded Atom Method ◽  
Vacancy Diffusion ◽  
Exchange Diffusion ◽  
Embedded Atom ◽  
And Diffusion ◽  
Step Edges

AbstractWe employ surface-embedded-atom-method potentials to investigate the diffusion barriers of vacancies diffusing over and near steps on the low index faces of silver. Barriers for vacancy terrace diffusion, diffusion over step-edges, and diffusion along step edges, including around corners, are calculated. Vacancies are significantly less mobile than adatoms and have large Ehrlich-Schwoebel (ES) barriers on all three faces. For Ag(100) the diffusion barrier for vacancies along step-edges is virtually the same (474 meV) as on the terrace. As in diffusion near the step edge, vacancies encounter a significant increase (213 meV) in the activation barrier when diffusing around the corner of a vacancy island (the corner analogue of the ES barrier), but the excess barrier around a kink all but disappears because exchange diffusion is favorable there. The consequences of the vacancy diffusion barriers on 3D pitting and on island diffusion and coarsening are discussed.

Flat-surface, step-edge, facet–facet, and facet–step diffusion barriers in growth of a Pb mesa

2008 ◽  
Vol 602 (13) ◽  
pp. 2284-2294 ◽  
Author(s):  
Yong Han ◽  
Guang-Hong Lu ◽  
Byeong-Joo Lee ◽  
Feng Liu
Keyword(s):  
Flat Surface ◽  
Diffusion Barriers ◽  
Step Edge ◽  
Surface Step

scholarly journals Influence of The Electrochemical Environment on Diffusion Processes Near Step and Island Edges: Ag(111) and Ag(100)

1999 ◽  
Vol 580 ◽  
Author(s):  
Michael I. Haftel ◽  
T. L. Einstein
Keyword(s):  
Surface Charge ◽  
Diffusion Processes ◽  
Diffusion Barriers ◽  
Step Edge ◽  
Metallic Surfaces ◽  
Embedded Atom ◽  
Powerful Means ◽  
Coarsening Dynamics ◽  
Coarsening Kinetics ◽  
Monotonically Decrease

AbstractThe electrochemical cell provides a potentially powerful means of altering morphology and islanding phenomena on metallic surfaces. Diffusion and attachment processes on terraces and near step and island edges are known to profoundly affect island sizes, shapes and coarsening kinetics. Using the surface-embedded-atom-model (SEAM) for describing metallic surfaces in the electrolytic environment, we calculate the dependence of the activation energies for the aforementioned diffusion processes on the deposited surface charge for the Ag(111) and Ag(100) surfaces in an electrolytic environment. While all these processes show some degree of dependence on the potential, the step-edge barrier and the edge diffusion processes are the most sensitive. Step-edge barriers increase (to over 1 eV) with large positive potential (0.85 V), while edge diffusion barriers monotonically decrease with positive surface charge on Ag(100) and Ag(111). We assess the effect these diffusion barriers have on island size/shapes and coarsening dynamics and discuss the implications on electrochemical tuning of islanding phenomena.

Biological and Surface Properties of C-Type Virus Particles Produced by Novikoff Ascites Hepatoma Cells

1977 ◽  
Vol 35 ◽  
pp. 388-389
Author(s):  
D.C. Hixson ◽  
J.C. Chan ◽  
J.M. Bowen ◽  
E.F. Walborg
Keyword(s):  
Surface Properties ◽  
Ricinus Communis ◽  
Rat Kidney ◽  
Leukemia Virus ◽  
Viral Envelope ◽  
Virus Particles ◽  
Chemically Induced ◽  
Sarcoma Virus ◽  
Hepatocarcinoma Cells ◽  
Type C

Several years ago Karasaki (1) reported the production of type C virus particles by Novikoff ascites hepatocarcinoma cells. More recently, Weinstein (2) has reported the presence of type C virus particles in cell cultures derived from transplantable and primary hepatocellular carcinomas. To date, the biological function of these virus and their significance in chemically induced hepatocarcinogenesis are unknown. The present studies were initiated to determine a possible role for type C virus particles in chemically induced hepatocarcinogenesis. This communication describes results of studies on the biological and surface properties of type C virus associated with Novikoff hepatocarcinoma cells.Ecotropic and xenotropic murine leukemia virus (MuLV) activity in ascitic fluid of Novikoff tumor-bearing rats was assayed in murine sarcoma virus transformed S+L- mouse cells and S+L- mink cells, respectively. The presence of sarcoma virus activity was assayed in non-virus-producing normal rat kidney (NRK) cells. Ferritin conjugates of concanavalin A (Fer-Con wheat germ agglutinin (Fer-WGA), and Ricinus communis agglutinins I and II (Fer-RCAI and Fer-RCAII) were used to probe the structure and topography of saccharide determinants present on the viral envelope.

Stress Relaxation and the Formation of Silicides in the Process of the Crystallization of NI-NB Films on SI

1991 ◽  
Vol 49 ◽  
pp. 898-899
Author(s):  
N. Rozhanski ◽  
V. Lifshitz
Keyword(s):  
Thin Films ◽  
Stress Relaxation ◽  
Integrated Circuits ◽  
Direct Evidence ◽  
Alloy Film ◽  
Diffusion Barriers ◽  
Effective Barrier

Thin films of amorphous Ni-Nb alloys are of interest since they can be used as diffusion barriers for integrated circuits on Si. A native SiO2 layer is an effective barrier for Ni diffusion but it deformation during the crystallization of the alloy film lead to the appearence of diffusion fluxes through it and the following formation of silicides. This study concerns the direct evidence of the action of stresses in the process of the crystallization of Ni-Nb films on Si and the structure of forming NiSi2 islands.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

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