In situ HREM Study on the Thermal Stability of Atomic Layer Epitaxy Grown InAs/GaAs Quantum Dots

2004 ◽  
Vol 839 ◽  
Author(s):  
H. S. Kim ◽  
J. H. Suh ◽  
C. G. Park ◽  
S. J. Lee ◽  
S. K. Noh ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Quantum Dots ◽  
Early Stage ◽  
Atomic Layer ◽  
High Resolution Electron Microscopy ◽  
Atomic Layer Epitaxy ◽  
Average Height ◽  
In Situ Heating ◽  
Thermal Stability Of

ABSTRACTSelf-assembled InAs/GaAs quantum dots (QDs) were grown by the atomic layer epitaxy technique and the structure and the thermal stability of QDs have been studied by using high resolution electron microscopy with in-situ heating experiment capability. The QDs were found to form a hemispherical structure with {136} side facet in the early stage of growth. The average height and diameter of the QD were found to be ∼ 5.5 nm and ∼ 23 nm, respectively. Upon capping by GaAs layer, however, the apex structure of QD changed to a flat one. In-situ heating experiment within TEM revealed that the uncapped QD remained stable until 580°C. However, at temperature above 600°C, the QD structure became flat due to the fast decrease of QD height. After flattening, the atoms diffused from the InAs QD to the GaAs substrate, resulting in the total collapse. The density of the QD decreased abruptly by this collapse and most QDs disappeared at above 600°C.

Structure and thermal stability of InAs/GaAs quantum dots grown by atomic layer epitaxy and molecular beam epitaxy

2005 ◽  
Vol 285 (1-2) ◽  
pp. 137-145 ◽  
Author(s):  
Hyung Seok Kim ◽  
Ju Hyung Suh ◽  
Chan Gyung Park ◽  
Sang Jun Lee ◽  
Sam Kyu Noh ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Quantum Dots ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Thermal Stability Of

scholarly journals Thermal stability of helium bubble superlattice in Mo under TEM in-situ heating

2018 ◽  
Vol 505 ◽  
pp. 207-211 ◽  
Author(s):  
Jian Gan ◽  
Cheng Sun ◽  
Lingfeng He ◽  
Yongfeng Zhang ◽  
Chao Jiang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Helium Bubble ◽  
In Situ Heating ◽  
Thermal Stability Of

scholarly journals In situ study of the thermal stability of supported Pt nanoparticles and their stabilization via atomic layer deposition overcoating

Nanoscale ◽  
2020 ◽  
Vol 12 (21) ◽  
pp. 11684-11693
Author(s):  
Eduardo Solano ◽  
Jolien Dendooven ◽  
Ji-Yu Feng ◽  
Philipp Brüner ◽  
Matthias M. Minjauw ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Atomic Layer Deposition ◽  
Pt Nanoparticles ◽  
Atomic Layer ◽  
Pt Nanoparticle ◽  
In Situ Study ◽  
Layer Deposition ◽  
Nanoparticle Stabilization ◽  
Thermal Stability Of

Supported Pt nanoparticle stabilization via Atomic Layer Deposition overcoating with Al2O3 has been proved to prevent particle coarsening during thermal annealing for widely spaced nanoparticles while ensuring surface accessibility for applications.

scholarly journals Structural Core-Shell beyond Chemical Homogeneity in Non-Stoichiometric Cu5FeS4 Nano-Icosahedrons: An in Situ Heating TEM Study

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 4 ◽  
Author(s):  
Bin Zhang ◽  
Xiaowei Zhao ◽  
Tianrui Dong ◽  
Aijuan Zhang ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Core Shell ◽  
Practical Applications ◽  
The Core ◽  
Shell Nanostructures ◽  
In Situ Heating ◽  
Intrinsic Strain ◽  
Thermal Stability Of

Thermal stability of core-shell structured nanoparticles is of vital importance to their practical applications at elevated temperature. Understanding the evolution of chemical distribution and the crystal structure of core-shell nanostructures with temperature variation at the nanoscale will open the route for practical applications and property enhancement of nanoparticles through proper design of new nanomaterials. In this study, core-shell non-stoichiometric Cu5FeS4 icosahedral nanoparticles were investigated by in situ heating transmission electron microscopy. Compared to the high structural and compositional stability at room temperature, the interdiffusion of Cu and Fe atoms became significant, ending up with disappearance of chemical difference in the core and shell over 300 °C. In contrast, different crystal structures of the core and shell were preserved even after heating at 350 °C, indicating the high structural stability. The inconsistency between chemical composition and crystal structure should be ascribed to the interaction between the intrinsic strain existing in the icosahedrons and various structures of this material system. In other words, the geometrically intrinsic strain of the nano-icosahedrons is helpful to modulate/maintain the core-shell structure. These findings open new opportunities for revealing the thermal stability of core-shell nanostructures for various applications and are helpful for the controllable design of new core-shell nanostructures.

Thermal stability of self-assembled ordered three-phase Au–BaTiO3–ZnO nanocomposite thin films via in situ heating in TEM

Nanoscale ◽  
2020 ◽  
Vol 12 (46) ◽  
pp. 23673-23681
Author(s):  
Shikhar Misra ◽  
Di Zhang ◽  
Ping Lu ◽  
Haiyan Wang
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Ex Situ ◽  
Three Phase ◽  
Nanocomposite Thin Films ◽  
Vertically Aligned ◽  
In Situ Heating ◽  
Self Assembled ◽  
Thermal Stability Of

Thermal stability of an ordered three-phase Au–BaTiO3–ZnO vertically aligned nanostructure by both ex situ annealing under air and vacuum conditions, and in situ heating in TEM in vacuum has been demonstrated.

Thermal Stability of Atomic Layer Deposited Zr:Al Mixed Oxide Thin Films: An in Situ Transmission Electron Microscopy Study

2005 ◽  
Vol 20 (7) ◽  
pp. 1741-1750
Author(s):  
L.C. Nistor ◽  
O. Richard ◽  
C. Zhao ◽  
H. Bender ◽  
G. Van Tendeloo
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Atomic Layer ◽  
Silicon Surfaces ◽  
Transmission Electron ◽  
Thermal Stability Of

The thermal stability of amorphous Zr:Al mixed oxide films of different composition, produced on (001) silicon wafers by the atomic layer deposition method is studied by transmission electron microscopy during in situ heating experiments. The temperatures at which phase separation and crystallization occur are composition dependent. The crystallization of thick films (55–70 nm), deposited on HF-treated silicon surfaces covered with a 15 cycles Al2O3 layer, results in the formation of cubic ZrO2 and cubic γ–Al2O3. In very thin films (5 nm), deposited on silicon surfaces covered with a 0.5 nm SiO2 thin film, the formation of tetragonal zirconium disilicide (ZrSi2) is observed in the microscope vacuum, at temperatures above 900 °C. This effect depends on the thickness of the as deposited thin film.

Thermal stability of C-F/C-F2 bonds in fluorinated graphene detected by in-situ heating infrared spectroscopy

2021 ◽  
Author(s):  
Yulong Li ◽  
Jingliang Cheng ◽  
Xu Wang ◽  
Yang Liu ◽  
Xiangyang Liu
Keyword(s):  
Thermal Stability ◽  
Infrared Spectroscopy ◽  
In Situ Heating ◽  
Fluorinated Graphene ◽  
Thermal Stability Of

Thermal stability of fluorinated graphene (FG) plays an important role in its application and research, so it is necessary to conduct in-depth research on thermal stability of C-F bond in...

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