Onset of C(2×2) ferrimagnetic order in Cr islands deposited on Fe(001) as a function of island size

1996 ◽  
Vol 79 (8) ◽  
pp. 5834 ◽  
Author(s):  
L. Pizzagalli ◽  
D. Stoeffler ◽  
A. Vega ◽  
S. Bouarab ◽  
C. Demangeat ◽  
...  
Keyword(s):  
Island Size

Effect Of Phosphorus On Ge/Si(001) Island Formation

2002 ◽  
Vol 737 ◽  
Author(s):  
Theodore I. Kamins ◽  
Gilberto Medeiros-Ribeiro ◽  
Douglas A. A. Ohlberg ◽  
R. Stanley Williams
Keyword(s):  
Deposition Rate ◽  
Strain Energy ◽  
Competitive Adsorption ◽  
Lattice Mismatch ◽  
Three Dimensional ◽  
Deposition Process ◽  
Thin Layers ◽  
Island Size ◽  
Partial Pressures ◽  
Intermediate Size

ABSTRACTWhen Ge is deposited epitaxially on Si, the strain energy from the lattice mismatch causes the Ge in layers thicker than about four monolayers to form distinctive, three-dimensional islands. The shape of the islands is determined by the energies of the surface facets, facet edges, and interfaces. When phosphorus is added during the deposition, the surface energies change, modifying the island shapes and sizes, as well as the deposition process. When phosphine is introduced to the germane/hydrogen ambient during Ge deposition, the deposition rate decreases because of competitive adsorption. The steady-state deposition rate is not reached for thin layers. The deposited, doped layers contain three different island shapes, as do undoped layers; however, the island size for each shape is smaller for the doped layers than for the corresponding undoped layers. The intermediate-size islands are the most significant; the intermediate-size doped islands are of the same family as the undoped, multifaceted “dome” structures, but are considerably smaller. The largest doped islands appear to be related to the defective “superdomes” discussed for undoped islands. The distribution between the different island shapes depends on the phosphine partial pressure. At higher partial pressures, the smaller structures are absent. Phosphorus appears to act as a mild surfactant, suppressing small islands.

ISLAND-SIZE DISTRIBUTIONS OF Ag ON Pd(111)

1996 ◽  
Vol 03 (03) ◽  
pp. 1393-1402 ◽  
Author(s):  
R. FISCHER ◽  
TH. FAUSTER ◽  
W. VON DER LINDEN ◽  
V. DOSE
Keyword(s):  
Maximum Entropy Method ◽  
Entropy Method ◽  
Bayesian Probability ◽  
Magic Numbers ◽  
Size Distributions ◽  
Island Size ◽  
Two Phase ◽  
Two Photon ◽  
Small Clusters ◽  
Image State

Island-size distributions of submonolayer Ag films on Pd(111) adsorbed at 90 K and after annealing of the film are recovered from two-photon photoemission spectra of the first image state. The inversion of the ill-conditioned problem with the maximum-entropy method reveals magic numbers in the island-size distributions. Hypothesis testing within the framework of Bayesian probability theory indicates a critical nucleus size i=1. After annealing of the film large islands coexist with small clusters in a two-phase state.

Total Energy Differences Between Silicon Carbide Polytypes and their Implications for Crystal Growth

1997 ◽  
Vol 492 ◽  
Author(s):  
Sukit Llmpijumnong ◽  
Walter R. L. Lambrecht
Keyword(s):  
Silicon Carbide ◽  
Crystal Growth ◽  
Epitaxial Growth ◽  
Size Effects ◽  
Nearest Neighbor ◽  
Orbital Method ◽  
Full Potential ◽  
Neighbor Interaction ◽  
Island Size ◽  
Annni Model

ABSTRACTThe energy differences between various SiC polytypes are calculated using the full-potential linear muffin-tin orbital method and analyzed in terms of the anisotropie next nearest neighbor interaction (ANNNI) model. The fact that J1 + 2J2 < 0 with J1 > 0 implies that twin boundaries in otherwise cubic material are favorable unless twins occur as nearest neighbor layers. Contrary to some other recent calculations we find J1 > |J2|. We discuss the consequences of this for stabilization of cubic SiC in epitaxial growth, including considerations of the island size effects.

Ant communities on small tropical islands: effects of island size and isolation are obscured by habitat disturbance and ‘tramp’ ant species

2010 ◽  
Vol 37 (2) ◽  
pp. 229-236 ◽  
Author(s):  
Akhmad Rizali ◽  
David J. Lohman ◽  
Damayanti Buchori ◽  
Lilik Budi Prasetyo ◽  
Hermanu Triwidodo ◽  
...  
Keyword(s):  
Habitat Disturbance ◽  
Tropical Islands ◽  
Island Size ◽  
Ant Communities ◽  
Tramp Ant

Spatial Correlations in Growing Films

2000 ◽  
Vol 619 ◽  
Author(s):  
M.C. Bartelt
Keyword(s):  
Size Distribution ◽  
Lattice Gas ◽  
Mean Field ◽  
Film Deposition ◽  
Nucleation Theory ◽  
Spatial Correlations ◽  
Island Size ◽  
Pit Formation ◽  
Free Region ◽  
Lattice Gas Models

ABSTRACTDetailed analyses of non-equilibrium lattice-gas models of island nucleation and growth during film deposition (or etching) have been invaluable in elucidating basic issues in nucleation theory, deviations from mean-field predictions, and experimental observations. Particularly interesting and useful is the behavior of spatial correlations in the adlayer which develop during island (or pit) formation. In particular, a strong depletion in the population of island pairs at separations smaller than the average follows from depletion in the density of diffusing adspecies near islands. This feature delays percolation of clusters of coalesced islands. Another recently discovered and more subtle feature is a strong correlation between the width of the island-free region surrounding an island and the size and growth rate of that island. This direct correlation between island sizes and separations controls the shape of the island size distribution. If incorporated into rate-equation descriptions, it recovers the exact form of the scaling function for the island size distribution.

Growth of Niobium Films at High Temperatures on Sapphire

1996 ◽  
Vol 440 ◽  
Author(s):  
T. Wagner
Keyword(s):  
High Temperatures ◽  
Basal Plane ◽  
Misfit Strain ◽  
High Energy ◽  
Total Density ◽  
Initial Growth ◽  
Island Size ◽  
Transmission Electron ◽  
Orientation Density

AbstractThe growth and microstructural evolution of Nb thin films on the basal plane of α-Al2O3 were studied at different growth temperatures. The influence of island orientation, density, and misfit strain energy on the growth behavior of Nb films on (0001)α-Al2O3 at high temperatures has been investigated. The films were grown by MBE at 900°C and 1100°C. At these temperatures the Nb grows in the Volmer-Weber growth mode on the basal plane. In-situ reflection high energy electron diffraction (RHEED), Auger electron spectroscopy (AES) and transmission electron microscopy (TEM) investigations revealed that in the initial growth stage, Nb nuclei with different epitaxial orientations were formed. This leads to different orientations of thicker Nb films at different growth temperatures. At a growth temperature of 900°C the Nb{111} planes are parallel to the sapphire basal plane whereas at 1100°C Nb grows with the {110) planes parallel to the basal plane of sapphire. The formation of two different epitaxial orientations of thick Nb films can only be explained by considering both the change in the total density of Nb islands with temperature and the influence of island size on their total energy.

Fabrication of Glass Mixing Channels and Silicon Detection Cell with 45˚ Mirror Surfaces for the Indophenol Sensing Device

2005 ◽  
Vol 475-479 ◽  
pp. 1849-1852
Author(s):  
Kyu Shik Shin ◽  
Joon Shik Park ◽  
Kwang Bum Park ◽  
Hyo Derk Park ◽  
Jeong Rim Kim ◽  
...  
Keyword(s):  
Silicon Wafer ◽  
Tetramethylammonium Hydroxide ◽  
The Other ◽  
Anodic Bonding ◽  
Glass Wafer ◽  
Island Size ◽  
Hene Laser ◽  
Propyl Alcohol ◽  
Detection Cell ◽  
Bonding Method

Design and fabrication of micro mixing cells and detection cells were investigated. Glass micro mixing cells with island structures among channels were fabricated using sand blaster methods. Depth and width of mixing channel were 200 ㎛ and 180 ㎛ and island size was 90 ㎛ by 90 ㎛. Two 45° mirrors surfaces faced on each other in one detection cell which were fabricated by silicon anisotropic etching using 20% TMAH (Tetramethylammonium hydroxide) solution with 20% or 30% IPA (iso propyl alcohol) at 80°C, respectively. Up side glass wafer for mixing cell and down side silicon wafer for detection cell were bonded using anodic bonding method at 350ı, -600 V and 300 N. Synthetic indophenol was injected at inlet and moved to the detection cell through the mixing channel. HeNe laser of 632.8 nm was focused on one side of a 45° mirror, and passed through indophenol solution until the other side of a 45° mirror. The light of 632.8 nm was absorbed in indophenol solution between two 45° mirrors at detection cell. By the Beer-Lambert’s law, indophenol concentration could be calculated from the measured result of the absorbance.

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