scholarly journals In situ mechanical resonance behaviour of pristine and defective zinc blende GaAs nanowires

Nanoscale ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 2588-2595 ◽  
Author(s):  
Edmund Pickering ◽  
Arixin Bo ◽  
Haifei Zhan ◽  
Xiaozhou Liao ◽  
Hark Hoe Tan ◽  
...  
Keyword(s):  
Quality Factor ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Stacking Faults ◽  
Mechanical Resonance ◽  
Zinc Blende ◽  
Gaas Nanowires

Mechanical resonance of GaAs nanowires allows for measurement of the effect of stacking faults on Young's modulus and quality factor.

Effect of a High Density of Stacking Faults on the Young’s Modulus of GaAs Nanowires

Nano Letters ◽  
2016 ◽  
Vol 16 (3) ◽  
pp. 1911-1916 ◽  
Author(s):  
Yujie Chen ◽  
Tim Burgess ◽  
Xianghai An ◽  
Yiu-Wing Mai ◽  
H. Hoe Tan ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Stacking Faults ◽  
High Density ◽  
Gaas Nanowires

Mechanical Properties of Pyrolytic "SiOCN" Thin Coatings

1993 ◽  
Vol 308 ◽  
Author(s):  
Sandrine Bec ◽  
André Tonck ◽  
Jean-Luc Loubet
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ceramic Coatings ◽  
Optical Observation ◽  
Thin Coatings ◽  
Polymer Precursors ◽  
Polymeric State

ABSTRACTPyrolysis of polymer precursors (polysilazane) is a technologically and economically interesting way to produce thin ceramic coatings. However, many cracks appear and decohesion occurs during pyrolysis when the ceramic coatings (SiOCN) are thicker than 0.5 micrometers. In order to understand these cracking phenomena, the coatings are mechanically characterized by nanoindentation at different stages of the pyrolysis heat treatment.During pyrolysis, the cracking temperature is detected by in-situ optical observation. The thickness of the coatings varies during pyrolysis from 3 micrometers at the polymeric state to 1 micrometer at the ceramic state. The coatings' properties, hardness and Young's modulus are evaluated after heat treatment, taking into account the substrate's influence. A large variation of these properties occurs at the cracking temperature. Both the hardness and the Young's modulus are multiplied by a factor of 10. By analysing these results, we show that cracking is correlated with the evolution of the coatings' mechanical properties during the transformation.

scholarly journals Young’s Modulus of Polycrystalline Titania Microspheres Determined by In Situ Nanoindentation and Finite Element Modeling

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Peida Hao ◽  
Yanping Liu ◽  
Yuanming Du ◽  
Yuefei Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Deformation Mechanisms ◽  
Displacement Curve ◽  
Element Simulation ◽  
Nanoindentation Experiment ◽  
Force Displacement

In situ nanoindentation was employed to probe the mechanical properties of individual polycrystalline titania (TiO2) microspheres. The force-displacement curves captured by a hybrid scanning electron microscope/scanning probe microscope (SEM/SPM) system were analyzed based on Hertz’s theory of contact mechanics. However, the deformation mechanisms of the nano/microspheres in the nanoindentation tests are not very clear. Finite element simulation was employed to investigate the deformation of spheres at the nanoscale under the pressure of an AFM tip. Then a revised method for the calculation of Young’s modulus of the microspheres was presented based on the deformation mechanisms of the spheres and Hertz’s theory. Meanwhile, a new force-displacement curve was reproduced by finite element simulation with the new calculation, and it was compared with the curve obtained by the nanoindentation experiment. The results of the comparison show that utilization of this revised model produces more accurate results. The calculated results showed that Young’s modulus of a polycrystalline TiO2microsphere was approximately 30% larger than that of the bulk counterpart.

Parabolic-Apex Numerical Back-Analysis of Mechanics Parameters of Surrounding Rock

2012 ◽  
Vol 204-208 ◽  
pp. 196-201 ◽  
Author(s):  
Jian Cong Xu ◽  
Yi Wei Xu
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Pressure Coefficient ◽  
Back Analysis ◽  
Surrounding Rock ◽  
In Situ Monitoring ◽  
Monitoring Data ◽  
3D Fem ◽  
Physical Mechanics

The parabolic-apex numerical back-analysis method (PNBM) was proposed to obtain such physical-mechanics parameters as Young's modulus and lateral pressure coefficient of surrounding rock by 3D FEM numerical analysis based on in-situ monitoring data. Taking Xiang-an Subsea Tunnel (located in Xiamen, Fujian Province, China) for example, adopting the PNBM using ABAQUS software, three dimensional elastic-plastic FEM-PNBM of tunnel surrounding rock was validated using in-situ monitoring data. The results show as follows: Using the PNBM, not only may high calculation precision be obtained, better meeting the demand of actual projects, but also more reasonable and reliable physical mechanics indices of surrounding rock such as Young's modulus and lateral confinement pressure coefficient, may be obtained. The applicability and the simplicity of this proposed method also support its usefulness.

Stacking-Faults-Free Zinc Blende GaAs Nanowires

Nano Letters ◽  
2009 ◽  
Vol 9 (1) ◽  
pp. 215-219 ◽  
Author(s):  
Hadas Shtrikman ◽  
Ronit Popovitz-Biro ◽  
Andrey Kretinin ◽  
Moty Heiblum
Keyword(s):  
Stacking Faults ◽  
Zinc Blende ◽  
Gaas Nanowires ◽  
Free Zinc

An In Situ Measuring Method for Young's Modulus of a MEMS Film Base on Resonance Frequency

2012 ◽  
Vol 503 ◽  
pp. 308-311
Author(s):  
Han Chen ◽  
Hua Rong
Keyword(s):  
Thin Film ◽  
Resonance Frequency ◽  
Young’S Modulus ◽  
Circular Plate ◽  
Material Property ◽  
Young's Modulus ◽  
Measuring Method ◽  
Test Structure ◽  
Film Research

Large-scale measurement of material property is not suit for the MEMS thin-film. Research the in-situ measuring method for material property of the MEMS thin-film is urgently. A center-anchored circular plate is adopted as the test structure here. The resonance frequency of the circular plate is measured to extract the Young’s modulus of a MEMS thin-film. The accuracy of this non-contact in-situ measuring method has been verified by CoventorWare. The inferences of the stress gradient have been analyzed. The advantages of the test structure and the measuring method present here also have been discussed.

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