Layer-by-layer heteroepitaxial growth process of a BaO layer on SrTiO3(001) as investigated by molecular dynamics

1998 ◽  
Vol 109 (20) ◽  
pp. 9148-9154 ◽  
Author(s):  
Momoji Kubo ◽  
Yasunori Oumi ◽  
Ryuji Miura ◽  
Andras Stirling ◽  
Akira Miyamoto ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Growth Process ◽  
Layer By Layer ◽  
Heteroepitaxial Growth

Molecular dynamics simulation on a layer-by-layer homoepitaxial growth process of SrTiO3(001)

1998 ◽  
Vol 109 (19) ◽  
pp. 8601-8606 ◽  
Author(s):  
Momoji Kubo ◽  
Yasunori Oumi ◽  
Ryuji Miura ◽  
Andras Stirling ◽  
Akira Miyamoto ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Growth Process ◽  
Dynamics Simulation ◽  
Layer By Layer ◽  
Homoepitaxial Growth

Evolution of Metastable Structures in Bimetallic Catalysts from Microscopy and Machine-Learning Molecular Dynamics

2020 ◽  
Author(s):  
Jin Soo Lim ◽  
Jonathan Vandermause ◽  
Matthijs A. van Spronsen ◽  
Albert Musaelian ◽  
Christopher R. O’Connor ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Large Scale ◽  
Materials Science ◽  
Complete Characterization ◽  
Layer By Layer ◽  
Surface Restructuring ◽  
Metastable Structures ◽  
Mechanistic Investigation ◽  
Underlying Mechanisms

Restructuring of interface plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different composition and morphology at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of the long-timescale restructuring of Pd deposited on Ag, using microscopy, spectroscopy, and novel simulation methods. Encapsulation of Pd by Ag always precedes layer-by-layer dissolution of Pd, resulting in significant Ag migration out of the surface and extensive vacancy pits. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. The underlying mechanisms are uncovered by performing fast and large-scale machine-learning molecular dynamics, followed by our newly developed method for complete characterization of atomic surface restructuring events. Our approach is broadly applicable to other multimetallic systems of interest and enables the previously impractical mechanistic investigation of restructuring dynamics.

Heteroepitaxial Nucleation and Growth of Ge ON Si(100) Surfaces Using Remote Plasma Enhanced Chemical Vapor Deposition

1988 ◽  
Vol 116 ◽  
Author(s):  
R.A. Rudder ◽  
S.V. Hattangady ◽  
D.J. Vitkavage ◽  
R.J. Markunas
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Layer By Layer ◽  
Heteroepitaxial Growth ◽  
Remote Plasma ◽  
Dimensional Growth ◽  
Diffraction Patterns

Heteroepitaxial growth of Ge on Si(100) has been accomplished using remote plasma enhanced chemical vapor deposition at 300*#x00B0;C. Reconstructed surfaces with diffraction patterns showing non-uniform intensity variations along the lengths of the integral order streaks are observed during the first 100 Å of deposit. This observation of an atomically rough surface during the initial stages of growth is an indication of three-dimensional growth. As the epitaxial growth proceeds, the diffraction patterns become uniform with extensive streaking on both the integral and fractional order streaks. Subsequent growth, therefore, takes place in a layer-by-layer, two-dimensional mode. X-ray photoelectron spectroscopy of the early nucleation stages, less than 80 Å, show that there is uniform coverage with no evidence of island formation.

scholarly journals Evolution of Metastable Structures at Bimetallic Surfaces from Microscopy and Machine-Learning Molecular Dynamics

2020 ◽  
Author(s):  
Jin Soo Lim ◽  
Jonathan Vandermause ◽  
Matthijs A. van Spronsen ◽  
Albert Musaelian ◽  
Yu Xie ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Materials Science ◽  
Automated Analysis ◽  
Layer By Layer ◽  
Surface Restructuring ◽  
Bimetallic Systems ◽  
Metastable Structures ◽  
Mechanistic Investigation ◽  
First Time

Restructuring of interfaces plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different composition and morphology at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of long-timescale restructuring of Pd deposited on Ag, using microscopy, spectroscopy, and novel simulation methods. By developing and performing accelerated machine-learning molecular dynamics followed by an automated analysis method, we discover and characterize previously unidentified surface restructuring mechanisms in an unbiased fashion, including Pd-Ag place exchange and Ag pop-out, as well as step ascent and descent. Remarkably, layer-by-layer dissolution of Pd into Ag is always preceded by an encapsulation of Pd islands by Ag, resulting in a significant migration of Ag out of the surface and a formation of extensive vacancy pits within a period of microseconds. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. Our approach is broadly applicable to complex multimetallic systems and enables the previously intractable mechanistic investigation of restructuring dynamics at atomic resolution.

Surfactant-Mediated Epitaxial Growth of Metallic Thin Films

2010 ◽  
Vol 117 ◽  
pp. 55-61
Author(s):  
Masao Kamiko ◽  
Ryoichi Yamamoto
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Epitaxial Growth ◽  
Film Growth ◽  
Thin Film Growth ◽  
Growth Mode ◽  
Metallic Thin Films ◽  
Layer By Layer ◽  
Metallic Films ◽  
Heteroepitaxial Growth

The effects of several surfactants on the homoepitaxial and heteroepitaxial growth of metallic films and multilayers have been studied and compared. Our measurements clearly revealed that pre-deposition of a small amount of surfactant prior to the adatom deposition changed thin film growth mode and structure. The pre-deposited surfactant enhanced layer-by-layer (LBL) growth of the homoepitaxial and heteroepitaxial growth of metallic films. The surfactant also enhanced the epitaxial growth of metallic multilayer.

II-VI Material Integration With Silicon for Detector and PV Applications

MRS Advances ◽  
2016 ◽  
Vol 1 (50) ◽  
pp. 3391-3402 ◽  
Author(s):  
T.A. Gessert ◽  
E. Colegrove ◽  
B. Stafford ◽  
R. Kodama ◽  
Wei Gao ◽  
...  
Keyword(s):  
Growth Process ◽  
High Efficiency ◽  
Photovoltaic Devices ◽  
Heteroepitaxial Growth ◽  
Ir Detector ◽  
Ir Detectors ◽  
Growth Environment ◽  
Si Substrates ◽  
Conversion Efficiencies

ABSTRACTHeteroepitaxial growth of high-quality II-VI-alloy materials on Si substrates is a well-established commercial growth process for infrared (IR) detector devices. However, it has only recently been recognized that these same processes may have important applications for production of high-efficiency photovoltaic devices. This submission reviews the process developments that have enabled effective heteroepitaxy of II-VI alloy materials on lattice-mismatched Si for IR detectors as a foundation to describe recent efforts to apply these insights to the fabrication of multijunction Si/CdZnTe devices with ultimate conversion efficiencies >40%. Reviewed photovoltaic studies include multijunction Si/CdZnTe devices with conversion efficiency of ∼17%, analysis of structural and optoelectrical quality of undoped CdTe epilayer films on Si, and the effect that a Te-rich growth environment has on the structural and optoelectronic quality of both undoped and As-doped heteroepitaxial CdTe.

On Stabilization of 3C-SiC Using Low Off-Axis 6H-SiC Substrates

2012 ◽  
Vol 717-720 ◽  
pp. 193-196 ◽  
Author(s):  
Valdas Jokubavicius ◽  
Björn Lundqvist ◽  
Philip Hens ◽  
Rickard Liljedahl ◽  
Rositza Yakimova ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Growth Process ◽  
High Growth ◽  
Potential Method ◽  
High Growth Rate ◽  
Heteroepitaxial Growth ◽  
Bulk Properties ◽  
Combined Use ◽  
Sublimation Growth

Heteroepitaxial growth of 3C-SiC on 0.8 and 1.2 degree off-oriented 6H-SiC substrates was studied using a sublimation growth process. The 3C-SiC layers were grown at high growth rates with layer thickness up to 300 µm. The formation and the quality of 3C-SiC are influenced by the off-orientation of the substrate, the growth temperature (studied temperature range from 1750 °C to 1850°C), and the growth ambient (vacuum at 5*10-5mbar and nitrogen at 5*10-1mbar). The largest domains of 3C-SiC and the lowest number of double positioning boundaries were grown using nitrogen ambient and the highest growth temperature. The combined use of low off-axis substrate and high growth rate is a potential method to obtain material with bulk properties.

Surfactant Mediated Epitaxial Growth of Co on Au(111) Surface

2002 ◽  
Vol 749 ◽  
Author(s):  
Masao Kamiko ◽  
Sang-Mun Oh ◽  
Hiroaki Chihaya ◽  
Hiroyuki Mizuno ◽  
Junhua Xu ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Layer Thickness ◽  
Room Temperature ◽  
Surface Segregation ◽  
Growth Behavior ◽  
Layer By Layer ◽  
Heteroepitaxial Growth ◽  
Suitable Amount

ABSTRACTWe have chosen Bi as the surfactant atom in the heteroepitaxial growth of Co on Au(111). It was found that Bi induces layer-by-layer (LBL) growth at room temperature. With pre-deposition of 0.2 ∼ 0.8Å Bi on Au(111) prior to the evaporation of Co, more long-lasting RHEED intensity oscillations were observed and this implies that it induces the LBL growth of Co film. The result of the dependence of the growth behavior as a function of Bi layer thickness suggests that there is a suitable amount of Bi surfactant layer that induces the smoother LBL growth. A surface segregation of Bi was found at the top of surface and acts as a surfactant by promoting the interlayer transport.

Sign in / Sign up

Export Citation Format

Share Document