Focused Ion Beam Induced Surface Damage Effect on the Mechanical Properties of Silicon Nanowires

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Tatsuya Fujii ◽  
Takahiro Namazu ◽  
Koichi Sudoh ◽  
Shouichi Sakakihara ◽  
Shozo Inoue
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Focused Ion Beam ◽  
Young's Modulus ◽  
Ion Beam ◽  
Surface Damage ◽  
Ambient Air ◽  
Film Deposition ◽  
Displacement Sensor ◽  
Uniaxial Tensile

In this paper, the effect of surface damage induced by focused ion beam (FIB) fabrication on the mechanical properties of silicon (Si) nanowires (NWs) was investigated. Uniaxial tensile testing of the NWs was performed using a reusable on-chip tensile test device with 1000 pairs of comb structures working as an electrostatic force actuator, a capacitive displacement sensor, and a force sensor. Si NWs were made from silicon-on-nothing (SON) membranes that were produced by deep reactive ion etching hole fabrication and ultrahigh vacuum annealing. Micro probe manipulation and film deposition functions in a FIB system were used to bond SON membranes to the device's sample stage and then to directly fabricate Si NWs on the device. All the NWs showed brittle fracture in ambient air. The Young's modulus of 57 nm-wide NW was 107.4 GPa, which was increased to 144.2 GPa with increasing the width to 221 nm. The fracture strength ranged from 3.9 GPa to 7.3 GPa. By assuming the thickness of FIB-induced damage layer, the Young's modulus of the layer was estimated to be 96.2 GPa, which was in good agreement with the literature value for amorphous Si.

Influences of Specimen Size and Annealing Temperature on Mechanical Reliability of FIB-Fabricated Si Nanowires for NEMS

2013 ◽  
Author(s):  
Tatsuya Fujii ◽  
Koichi Sudoh ◽  
Shozo Inoue ◽  
Takahiro Namazu
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Ion Beam ◽  
High Vacuum ◽  
Specimen Size ◽  
Film Deposition ◽  
Uniaxial Tensile ◽  
Si Nanowires ◽  
Uniaxial Tensile Testing ◽  
The Mean

This paper describes the effects of specimen size, focused ion beam (FIB) induced damage, and annealing on the mechanical properties of sub-100nm-sized silicon (Si) nanowires (NWs) that were evaluated by means of uniaxial tensile testing. Si NWs were made from silicon-on-nothing membranes that were produced by deep reactive ion etching trench fabrication and ultra-high vacuum (UHV) annealing. FIB system’s probe manipulation and film deposition functions were used to fabricate Si NWs and to directly bond them onto the sample stage of a tensile test device. The mean Young’s modulus and the mean strength of FIB-damaged NWs were 131.0 GPa and 5.6 GPa, respectively. After 700°C and 1000°C annealing in UHV, the mean Young’s modulus was increased to 168.1 GPa and 169.4 GPa, respectively, due to recrystallization by annealing. However, the mean strength was decreased to 4.1 GPa and 4.0 GPa, respectively. These experimental facts imply that the crystallinity of NWs improved, but the morphology was degraded. The surface degradation was probably related to gallium ion implantation into NWs surface during FIB fabrication.

scholarly journals Atomic Simulations of Packing Structures, Local Stress and Mechanical Properties for One Silicon Lattice with Single Vacancy on Heating

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3127
Author(s):  
Feng Dai ◽  
Dandan Zhao ◽  
Lin Zhang
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Silicon Crystal ◽  
Local Stress ◽  
Uniaxial Tensile ◽  
Single Vacancy ◽  
Vacancy Defects ◽  
Silicon Lattice ◽  
Atomic Simulations

The effect of vacancy defects on the structure and mechanical properties of semiconductor silicon materials is of great significance to the development of novel microelectronic materials and the processes of semiconductor sensors. In this paper, molecular dynamics is used to simulate the atomic packing structure, local stress evolution and mechanical properties of a perfect lattice and silicon crystal with a single vacancy defect on heating. In addition, their influences on the change in Young’s modulus are also analyzed. The atomic simulations show that in the lower temperature range, the existence of vacancy defects reduces the Young’s modulus of the silicon lattice. With the increase in temperature, the local stress distribution of the atoms in the lattice changes due to the migration of the vacancy. At high temperatures, the Young’s modulus of the silicon lattice changes in anisotropic patterns. For the lattice with the vacancy, when the temperature is higher than 1500 K, the number and degree of distortion in the lattice increase significantly, the obvious single vacancy and its adjacent atoms contracting inward structure disappears and the defects in the lattice present complex patterns. By applying uniaxial tensile force, it can be found that the temperature has a significant effect on the elasticity–plasticity behaviors of the Si lattice with the vacancy.

Cellulose Whiskers Micro-Fibers Effect in the Mechanical Proprieties of PP and PLA Composites Fibers Obtained by Spinning Process

2011 ◽  
Vol 146 ◽  
pp. 12-26 ◽  
Author(s):  
A. Gherissi ◽  
R.Ben Cheikh ◽  
E. Dévaux ◽  
Fethi Abbassi
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Tensile Tests ◽  
Advanced Materials ◽  
Uniaxial Tensile ◽  
Failure Resistance ◽  
Cellulose Whiskers ◽  
Limit Strength

In this study, we present the manufacturing process of two new composites materials in the form of long fibers of polylactic-acid (PLA) or polypropylene (PP), reinforced by cellulose whiskers micro-fibers loads. In order to evaluate the mechanical properties of these advanced materials, a several uniaxial tensile tests were carried out. The PP and the PLA have initially been spinning without the addition of cellulose whiskers micro-fibers. In order to study the effects of cellulose whiskers micro-fibers reinforcements in the Mechanical behavior of the PLA and PP filaments, we determinate the proprieties of these advanced material from the tensile results. For the PP composite filaments material case, the whiskers reinforcement increases Young's modulus and failure resistance, but it reduces the limit strength failure. For the PLA composites the addition of 1% wt of cellulose whiskers from the total volume fraction of the material, increase the Young’s modulus more than 50% and a decrease of the failure resistance and the limit strength of composite. The obtained composites fibers are very rigid and brittle. What follows, that the addition of cellulose whiskers micro fibers in PP matrix, provides mechanical properties more convenient compared to the PLA matrix.

Uncertainty quantification and prediction for mechanical properties of graphene aerogels via gaussian process metamodels

Nano Futures ◽  
2021 ◽  
Author(s):  
Bowen Zheng ◽  
Zeyu Zheng ◽  
Grace Gu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Gaussian Process ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamics Simulation ◽  
Uniaxial Tensile ◽  
Graphene Aerogel ◽  
Graphene Aerogels

Abstract Graphene aerogels, a special class of 3D graphene assemblies, are well known for their exceptional combination of high strength, lightweightness, and high porosity. However, due to microstructural randomness, the mechanical properties of graphene aerogels are also highly stochastic, an issue that has been observed but insufficiently addressed. In this work, we develop Gaussian process metamodels to not only predict important mechanical properties of graphene aerogels but also quantify their uncertainties. Using the molecular dynamics simulation technique, graphene aerogels are assembled from randomly distributed graphene flakes and spherical inclusions, and are subsequently subject to a quasi-static uniaxial tensile load to deduce mechanical properties. Results show that given the same density, mechanical properties such as the Young’s modulus and the ultimate tensile strength can vary substantially. Treating density, Young’s modulus, and ultimate tensile strength as functions of the inclusion size, and using the simulated graphene aerogel results as training data, we build Gaussian process metamodels that can efficiently predict the properties of unseen graphene aerogels. In addition, statistically valid confidence intervals centered around the predictions are established. This metamodel approach is particularly beneficial when the data acquisition requires expensive experiments or computation, which is the case for graphene aerogel simulations. The present research quantifies the uncertain mechanical properties of graphene aerogels, which may shed light on the statistical analysis of novel nanomaterials of a broad variety.

Recycled HDPE-tetrapack composites. Isothermal crystallization, light scattering and mechanical properties

2012 ◽  
Vol 1485 ◽  
pp. 77-82 ◽  
Author(s):  
A Parada-Soria ◽  
HF Yao ◽  
B Alvarado-Tenorio ◽  
L Sanchez-Cadena ◽  
A Romo-Uribe
Keyword(s):  
Mechanical Properties ◽  
Light Scattering ◽  
Young’S Modulus ◽  
Tensile Deformation ◽  
Young's Modulus ◽  
Ultimate Tensile Stress ◽  
Uniaxial Tensile ◽  
Scanning Calorimetry ◽  
Slow Cooling ◽  
The Matrix

ABSTRACTIn this research the thermal and mechanical properties of composites based on recycled high-density polyethylene (HDPE) and recycled Tetrapak have been investigated. The matrix and filler are recovered from landfills. Multicolor HDPE mixtures, with varying concentration of tetrapack flakes, are hot pressed, as well as single color HDPE flakes. Previous studies determine that the nature of the pigment (organics vs. inorganics) strongly influence the mechanical behavior of multicolor HDPE-tetrapack composites. Thus, this research focuses on single color HDPE hot pressed plaques. The kinetics of crystallization under isothermal conditions is determined by differential scanning calorimetry (DSC). The results show that the crystallization kinetics obeys the Avrami theory, and that the Avrami exponent is 1, irrespective of the pigment in use. Small-angle light scattering is applied to investigate the internal structure of the pigmented HDPE. SALS patterns show that the samples exhibited oriented morphologies. However, after melting and slow cooling under pressure the samples exhibit an isotropic morphology. This is confirmed by polarized optical microscopy. Mechanical properties such as Young’s modulus, yield stress and ultimate tensile stress are obtained under uniaxial tensile deformation at room temperature. For the single color HDPE plaques the Young’s modulus is reduced (after melting), suggesting that the anisotropic molecular chains contribute to the higher value of Young’s modulus.

Measuring anisotropy in Young’s modulus of copper using microcantilever testing

2009 ◽  
Vol 24 (11) ◽  
pp. 3268-3276 ◽  
Author(s):  
David E.J. Armstrong ◽  
Angus J. Wilkinson ◽  
Steve G. Roberts
Keyword(s):  
Young’S Modulus ◽  
Focused Ion Beam ◽  
Young's Modulus ◽  
Ion Beam ◽  
Copper Sample ◽  
Critical Aspect ◽  
Electron Backscattered Diffraction ◽  
Single Grain ◽  
Fixed End ◽  
Good Agreement

Focused ion beam machining was used to manufacture microcantilevers 30 μm by 3 μm by 4 μm with a triangular cross section in single crystal copper at a range of orientations between. These were imaged and tested using AFM/nanoindentation. Each cantilever was indented multiple times at a decreasing distance away from the fixed end. Variation of the beam’s behavior with loading position allowed a critical aspect ratio (loaded length:beam width) of 6 to be identified above which simple beam approximations could be used to calculate Young’s modulus. Microcantilevers were also milled within a single grain in a polycrystalline copper sample and electron backscattered diffraction was used to identify the direction of the long axis of the cantilever. The experimentally measured values of Young’s modulus and their variation with orientation were found to be in good agreement with the values calculated from the literature data for bulk copper.

Height Dependence of Young's Modulus for Carbon Nanopillars Grown by Focused-Ion-Beam-Induced Chemical Vapor Deposition

2008 ◽  
Vol 47 (6) ◽  
pp. 5116-5119 ◽  
Author(s):  
Keiichiro Nonaka ◽  
Kojiro Tamaru ◽  
Masao Nagase ◽  
Hiroshi Yamaguchi ◽  
Shin'ichi Warisawa ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Young’S Modulus ◽  
Vapor Deposition ◽  
Focused Ion Beam ◽  
Young's Modulus ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Height Dependence
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