scholarly journals Deposition, Morphological, and Mechanical Evaluation of W and Be-Al2O3 and Er2O3 Co-Sputtered Films in Comparison with Pure Oxides

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1430
Author(s):  
Mihail Lungu ◽  
Cornel Staicu ◽  
Flaviu Baiasu ◽  
Alexandru Marin ◽  
Bogdan Butoi ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Hydrogen Permeation ◽  
Metallic Matrix ◽  
Thin Layers ◽  
Indentation Hardness ◽  
Force Microscopy ◽  
Sputtered Films ◽  
Oxide Addition ◽  
Atomic Force

Compact and defect-free high melting point oxide strengthened metallic matrix configurations are promising to resolve the hydrogen permeation and brittleness issues relevant to the fusion research community. Previous studies on oxide addition to metallic matrix demonstrated a mitigation in brittleness behavior, while deposition techniques and material configurations are still to be investigated. Thus, here, we report the structural, morphological, and mechanical characterization of metal-oxides thin layers co-deposited by radio frequency (RF)and direct current (DC) magnetron sputtering. A total of six configurations were deposited such as single thin layers of oxides (Al2O3, Er2O3) and co-deposition configurations as metal-oxides (W, Be)—(Al2O3, Er2O3). The study of films roughness by atomic force microscopy (AFM) method show that for Al2O3 metallic-oxides is increased to an extent that could favor gaseous trapping, while co-depositions with Be seem to promote an increased roughness and defects formation probability compared to W co-depositions. Lower elastic modulus on metal-oxide co-depositions was observed, while the indentation hardness increased for Be and decreased for W matrix configurations. These outputs are highly relevant for choosing the proper compact and trap-free configuration that could be categorized as a permeation barrier for hydrogen and furtherly studied in laborious permeation yield campaigns.

scholarly journals Fabrication and Characterization of InGaN Nano-scale Dots for Blue and Green LED Applications

2000 ◽  
Vol 5 (S1) ◽  
pp. 880-886
Author(s):  
K.S. Kim ◽  
C.-H. Hong ◽  
W.-H. Lee ◽  
C.S. Kim ◽  
O.H. Cha ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Visible Spectral Range ◽  
Thin Layers ◽  
Force Microscopy ◽  
Nano Scale ◽  
Atomic Force ◽  
Trapezoidal Shape ◽  
Transmission Electron ◽  
Green Led

Thin layers of InGaN were grown by metalorganic chemical vapor deposition and characterized with atomic force microscopy and high-resolution transmission electron microscopy. InGaN deposited on GaN exhibits a Stranski-Krastanov growth mode, including 2D wetting layer and 3D self-assembled quantum dots. Besides, we observed that the formed InGaN nano-scale dots have a trapezoidal shape with a {1-102} facet with respect to (0002) surface. Visible spectral range from UV to green was easily obtained by changing InGaN quantum well thickness up to 2.3 nm.

Fabrication and Characterization of InGaN Nano-scale Dots for Blue and Green LED Applications

1999 ◽  
Vol 595 ◽  
Author(s):  
K.S. Kim ◽  
C.-H. Hong ◽  
W.-H. Lee ◽  
C.S. Kim ◽  
O.H. Cha ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Visible Spectral Range ◽  
Thin Layers ◽  
Force Microscopy ◽  
Nano Scale ◽  
Atomic Force ◽  
Trapezoidal Shape ◽  
Transmission Electron ◽  
Green Led

AbstractThin layers of InGaN were grown by metalorganic chemical vapor deposition and characterized with atomic force microscopy and high-resolution transmission electron microscopy. InGaN deposited on GaN exhibits a Stranski-Krastanov growth mode, including 2D wetting layer and 3D self-assembled quantum dots. Besides, we observed that the formed InGaN nano-scale dots have a trapezoidal shape with a {1-102} facet with respect to (0002) surface. Visible spectral range from UV to green was easily obtained by changing InGaN quantum well thickness up to 2.3 nm.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

Stereometric characterization of Dinizia excelsa Ducke wood from Amazon rainforest using atomic force microscopy

2021 ◽  
Author(s):  
Willian Silva Conceição ◽  
Ştefan Ţălu ◽  
Robert Saraiva Matos ◽  
Glenda Quaresma Ramos ◽  
Fidel Guereiro Zayas ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Amazon Rainforest ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dinizia Excelsa

scholarly journals A Universal Model for the Log-Normal Distribution of Elasticity in Polymeric Gels and Its Relevance to Mechanical Signature of Biological Tissues

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Arnaud Millet
Keyword(s):  
Elastic Modulus ◽  
Normal Distribution ◽  
Biological Tissues ◽  
Force Microscopy ◽  
Polymeric Gels ◽  
Atomic Force ◽  
Clear Explanation ◽  
Log Normal ◽  
Log Normal Distribution

The mechanosensitivity of cells has recently been identified as a process that could greatly influence a cell’s fate. To understand the interaction between cells and their surrounding extracellular matrix, the characterization of the mechanical properties of natural polymeric gels is needed. Atomic force microscopy (AFM) is one of the leading tools used to characterize mechanically biological tissues. It appears that the elasticity (elastic modulus) values obtained by AFM presents a log-normal distribution. Despite its ubiquity, the log-normal distribution concerning the elastic modulus of biological tissues does not have a clear explanation. In this paper, we propose a physical mechanism based on the weak universality of critical exponents in the percolation process leading to gelation. Following this, we discuss the relevance of this model for mechanical signatures of biological tissues.

In Situ Characterization of the Mechanical Behavior of Gecko's Spatulae by Atomic Force Microscopy

2013 ◽  
Vol 22 ◽  
pp. 85-93
Author(s):  
Shuang Yi Liu ◽  
Min Min Tang ◽  
Ai Kah Soh ◽  
Liang Hong
Keyword(s):  
Mechanical Behavior ◽  
Hierarchical Level ◽  
Intrinsic Properties ◽  
In Situ Characterization ◽  
Force Microscopy ◽  
Atomic Force ◽  
Theoretical Predictions ◽  
Multi Mode

In-situ characterization of the mechanical behavior of geckos spatula has been carried out in detail using multi-mode AFM system. Combining successful application of a novel AFM mode, i.e. Harmonix microscopy, the more detail elastic properties of spatula is brought to light. The results obtained show the variation of the mechanical properties on the hierarchical level of a seta, even for the different locations, pad and stalk of the spatula. A model, which has been validated using the existing experimental data and phenomena as well as theoretical predictions for geckos adhesion, crawling and self-cleaning of spatulae, is proposed in this paper. Through contrast of adhesive and craw ability of the gecko on the surfaces with different surface roughness, and measurement of the surface adhesive behaviors of Teflon, the most effective adhesion of the gecko is more dependent on the intrinsic properties of the surface which is adhered.

Measurement of Plasticity Gradients with Scanning Probe Microscopy

1993 ◽  
Vol 318 ◽  
Author(s):  
James D. Kiely ◽  
Dawn A. Bonnell
Keyword(s):  
Fracture Surface ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Ceramic System ◽  
Force Microscopy ◽  
Metal Fracture ◽  
Atomic Force ◽  
Metal Ceramic

ABSTRACTScanning Tunneling and Atomic Force Microscopy were used to characterize the topography of fractured Au /sapphire interfaces. Variance analysis which quantifies surface morphology was developed and applied to the characterization of the metal fracture surface of the metal/ceramic system. Fracture surface features related to plasticity were quantified and correlated to the fracture energy and energy release rate.

Sign in / Sign up

Export Citation Format

Share Document