Confinement Effects in Two-Dimensional Silicon Structures

2005 ◽  
Author(s):  
Jose´ A. Pascual-Gutie´rrez ◽  
Jayathi Y. Murthy ◽  
Raymond Viskanta
Keyword(s):  
Interatomic Potential ◽  
Silicon Film ◽  
Dynamical Behavior ◽  
Dispersion Curves ◽  
Primary Role ◽  
Face Centered Cubic ◽  
Two Dimensional ◽  
Confinement Effects ◽  
Free Standing ◽  
Silicon Structures

Two-dimensional silicon structures are currently attracting a great deal of attention due to their potential application in the electronic and energy sectors. Most published works have employed simple face-centered cubic (fcc) models in determining dispersion curves and density of states for silicon. In this paper we address confinement effects in silicon using a two- and three-body environment-dependent interatomic potential (EDIP). Dispersion curves for silicon thin films under free-standing boundary conditions are theoretically computed by means of the dynamical equation. We show how size confinement causes the emergence of new energy levels and a flattening of the dispersion curves, explaining the reduction of phonon group velocities with respect to bulk, and the change in the volumetric specific heat. Our results indicate when confinement effects begin to play a primary role in the dynamical behavior of the structure and allow the prediction of the number of atomic layers above which a silicon film can be considered thick in terms of its dynamical behavior.

Topotactic Growth of Free-Standing Two-Dimensional Perovskite Niobates with Low Symmetry Phase

Nano Letters ◽  
2021 ◽  
Author(s):  
Fei Zhou ◽  
Yang Li ◽  
Xingqi Liao ◽  
Shuren Lin ◽  
Haizeng Song ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Free Standing ◽  
Symmetry Phase ◽  
Low Symmetry

Mechanics of free-standing inorganic and molecular 2D materials

Nanoscale ◽  
2021 ◽  
Author(s):  
Xianghui Zhang ◽  
Andre Beyer
Keyword(s):  
Recent Progress ◽  
Mechanical Characterization ◽  
2D Materials ◽  
Two Dimensional ◽  
Free Standing ◽  
Inorganic As

The discovery of graphene has triggered a great interest in inorganic as well as molecular two-dimensional (2D) materials. In this review, we summarize recent progress in the mechanical characterization of...

Enhanced field emission performance of MXene-TiO2 composite film

Nanoscale ◽  
2021 ◽  
Author(s):  
Bingjun Yang ◽  
Jiangtao Chen ◽  
xiaonan Wu ◽  
Bao Liu ◽  
Lingyang Liu ◽  
...  
Keyword(s):  
Composite Film ◽  
Field Emission ◽  
Two Dimensional ◽  
Field Emission Display ◽  
Free Standing ◽  
Emission Performance ◽  
Field Emitters ◽  
Field Emission Performance

A facile method to produce MXene-TiO2 composite is demonstrated for enhanced field emission display applications. The field emission performance of two-dimensional free-standing and linear-shaped field emitters has been systematically investigated...

Dislocation-Stacking Fault Tetrahedron Interactions in Cu

2002 ◽  
Vol 124 (3) ◽  
pp. 329-334 ◽  
Author(s):  
B. D. Wirth ◽  
V. V. Bulatov ◽  
T. Diaz de la Rubia
Keyword(s):  
Edge Dislocation ◽  
Interatomic Potential ◽  
High Energy ◽  
Dislocation Motion ◽  
Shear Localization ◽  
Stacking Fault ◽  
Dynamics Simulation ◽  
High Energy Particle ◽  
Face Centered Cubic ◽  
Stacking Fault Tetrahedra

In copper and other face centered cubic metals, high-energy particle irradiation produces hardening and shear localization. Post-irradiation microstructural examination in Cu reveals that irradiation has produced a high number density of nanometer sized stacking fault tetrahedra. The resultant irradiation hardening and shear localization is commonly attributed to the interaction between stacking fault tetrahedra and mobile dislocations, although the mechanism of this interaction is unknown. In this work, we present results from a molecular dynamics simulation study to characterize the motion and velocity of edge dislocations at high strain rate and the interaction and fate of the moving edge dislocation with stacking fault tetrahedra in Cu using an EAM interatomic potential. The results show that a perfect SFT acts as a hard obstacle for dislocation motion and, although the SFT is sheared by the dislocation passage, it remains largely intact. However, our simulations show that an overlapping, truncated SFT is absorbed by the passage of an edge dislocation, resulting in dislocation climb and the formation of a pair of less mobile super-jogs on the dislocation.

The Elastic Moduli of Silver Thin Films Measured with a New Microtensile Tester

1991 ◽  
Vol 239 ◽  
Author(s):  
J. Ruud ◽  
D. Josell ◽  
A. L. Greer ◽  
F. Spaepen
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Diffraction Grating ◽  
Strain Measurement ◽  
Elastic Moduli ◽  
Two Dimensional ◽  
Bulk Crystals ◽  
Free Standing ◽  
Tensile Direction ◽  
Silver Thin Films

ABSTRACTA new design for a thin film microtensile tester is presented. The strain is measured directly on the free-standing thin film from the displacement of laser spots diffracted from a thin grating applied to its surface by photolithography. The diffraction grating is two-dimensional, allowing strain measurement both along and transverse to the tensile direction. In principle, both Young's modulus and Poisson's ratio of a thin film can be determined. Ag thin films with strong <111> texture were tested. The measured Young moduli agreed with those measured on bulk crystals, but the measured Poisson ratios were low, most likely due to slight transverse folding of the film that developed during the test.

A Novel Micromechanical Resonator Using Two-Dimensional Phononic Crystal Slab

2011 ◽  
Vol 254 ◽  
pp. 195-198
Author(s):  
Nan Wang ◽  
Fu Li Hsiao ◽  
Moorthi Palaniapan ◽  
Ming Lin Julius Tsai ◽  
Jeffrey B.W. Soon ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystal ◽  
Acoustic Resonance ◽  
Two Dimensional ◽  
Free Standing ◽  
Sensing Applications ◽  
Aln Film ◽  
Digital Transducers ◽  
Square Array ◽  
Quality Factor Q

Two-dimensional (2-D) Silicon phononic crystal (PnC) slab of a square array of cylindrical air holes in a 10μm thick free-standing silicon plate with line defects is characterized as a cavity-mode PnC resonator. Piezoelectric aluminum nitride (AlN) film is deployed as the inter-digital transducers (IDT) to transmit and detect acoustic waves, thus making the whole microfabrication process CMOS-compatible. Both the band structure of the PnC and the transmission spectrum of the proposed PnC resonator are analyzed and optimized using finite element method (FEM). The measured quality factor (Q factor) of the microfabricated PnC resonator is over 1,000 at its resonant frequency of 152.46MHz. The proposed PnC resonator shows promising acoustic resonance characteristics for RF communications and sensing applications.

Two-Dimensional Quantum Transport in Free-Standing InSb Nanosheets

Nano Letters ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 561-569 ◽  
Author(s):  
Ning Kang ◽  
Dingxun Fan ◽  
Jinhua Zhi ◽  
Dong Pan ◽  
Sen Li ◽  
...  
Keyword(s):  
Quantum Transport ◽  
Two Dimensional ◽  
Free Standing
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