scholarly journals Thermodynamic model of coherent island formation on vicinal substrate

2014 ◽  
Vol 115 (16) ◽  
pp. 163508 ◽  
Author(s):  
Xu Zhang ◽  
Yanguang Yu ◽  
Xiao-Hong Sun ◽  
Xiaomin Ren
Author(s):  
L. Hultman ◽  
C.-H. Choi ◽  
R. Kaspi ◽  
R. Ai ◽  
S.A. Barnett

III-V semiconductor films nucleate by the Stranski-Krastanov (SK) mechanism on Si substrates. Many of the extended defects present in the films are believed to result from the island formation and coalescence stage of SK growth. We have recently shown that low (-30 eV) energy, high flux (4 ions per deposited atom), Ar ion irradiation during nucleation of III-V semiconductors on Si substrates prolongs the 1ayer-by-layer stage of SK nucleation, leading to a decrease in extended defect densities. Furthermore, the epitaxial temperature was reduced by >100°C due to ion irradiation. The effect of ion bombardment on the nucleation mechanism was explained as being due to ion-induced dissociation of three-dimensional islands and ion-enhanced surface diffusion.For the case of InAs grown at 380°C on Si(100) (11% lattice mismatch), where island formation is expected after ≤ 1 monolayer (ML) during molecular beam epitaxy (MBE), in-situ reflection high-energy electron diffraction (RHEED) showed that 28 eV Ar ion irradiation prolonged the layer-by-layer stage of SK nucleation up to 10 ML. Otherion energies maintained layer-by-layer growth to lesser thicknesses. The ion-induced change in nucleation mechanism resulted in smoother surfaces and improved the crystalline perfection of thicker films as shown by transmission electron microscopy and X-ray rocking curve studies.


2002 ◽  
Author(s):  
Rudolf Zitny ◽  
Jiří Sestak ◽  
Alexander Tsiapouris ◽  
Lothar Linke

2021 ◽  
Vol 155 (2) ◽  
pp. 024506
Author(s):  
Wilfried B. Holzapfel ◽  
Stefan Klotz

Author(s):  
Alexander Bucknell ◽  
Matthew McGilvray ◽  
David R.H. Gillespie ◽  
Geoffrey Jones ◽  
Benjamin Collier

1999 ◽  
Vol 23 (7) ◽  
pp. 408-409
Author(s):  
Loutfy H. Madkour ◽  
R. M. Issa ◽  
I. M. El-Ghrabawy

This investigation is designed to apply an advanced kinetic–thermodynamic model on the data obtained from acidic and alkaline corrosion of aluminium using bis- and mono-azo dyes as corrosion inhibitors.


1999 ◽  
Vol 23 (8) ◽  
pp. 518-519
Author(s):  
Francisco Jose Alguacil ◽  
Jaime Simpson ◽  
Patricio Navarro

A previously determined thermodynamic model for extraction equilibrium is used as a basis to predict experimentally measured distribution coefficients for the CuSO4–H2SO4–LIX 984–Escaid 103 solvent extraction system at 25 °C and aqueous copper concentrations in the range 0.01–2.0 gL−1, the copper loading isotherm is also obtained.


Author(s):  
Karl Yngve Lervåg ◽  
Hans Langva Skarsvåg ◽  
Eskil Aursand ◽  
Jabir Ali Ouassou ◽  
Morten Hammer ◽  
...  

1996 ◽  
Vol 457 ◽  
Author(s):  
R. Banerjee ◽  
X. D. Zhang ◽  
S. A. Dregia ◽  
H. L. Fraser

ABSTRACTNanocomposite Ti/Al multilayered thin films have been deposited by magnetron sputtering. These multilayers exhibit interesting structural transitions on reducing the layer thickness of both Ti and Al. Ti transforms from its bulk stable hep structure to fee and Al transforms from fee to hep. The effect of ratio of Ti layer thickness to Al layer thickness on the structural transitions has been investigated for a constant bilayer periodicity of 10 nm by considering three different multilayers: 7.5 nm Ti / 2.5 nm Al, 5 nm Ti / 5 nm Al and 2.5 nm Ti / 7.5 nm Al. The experimental results have been qualitatively explained on the basis of a thermodynamic model. Preliminary experimental results of interfacial reactions in Ti/Al bilayers resulting in the formation of Ti-aluminides are also presented in the paper.


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