scholarly journals Size-dependent structural characteristics and phonon thermal transport in silicon nanoclusters

AIP Advances ◽  
2013 ◽  
Vol 3 (8) ◽  
pp. 082114 ◽  
Author(s):  
Hai-Peng Li ◽  
Rui-Qin Zhang
Keyword(s):  
Thermal Transport ◽  
Structural Characteristics ◽  
Silicon Nanoclusters ◽  
Size Dependent

Grain-Size-Dependent Thermal Transport Properties in Nanocrystalline Yttria-Stabilized Zirconia

2001 ◽  
Vol 703 ◽  
Author(s):  
Ho-Soon Yang ◽  
J.A. Eastman ◽  
L.J. Thompson ◽  
G.-R. Bai
Keyword(s):  
Grain Boundaries ◽  
Thermal Transport ◽  
Chemical Vapor ◽  
Yttria Stabilized Zirconia ◽  
Organic Chemical ◽  
Stabilized Zirconia ◽  
Size Dependent ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTUnderstanding the role of grain boundaries in controlling heat flow is critical to the success of many envisioned applications of nanocrystalline materials. This study focuses on the effect of grain boundaries on thermal transport behavior in nanocrystalline yttria-stabilized zirconia (YSZ) coatings prepared by metal-organic chemical vapor deposition.

scholarly journals Size-dependent phononic thermal transport in low-dimensional nanomaterials

2020 ◽  
Vol 860 ◽  
pp. 1-26 ◽  
Author(s):  
Zhongwei Zhang ◽  
Yulou Ouyang ◽  
Yuan Cheng ◽  
Jie Chen ◽  
Nianbei Li ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Size Dependent ◽  
Low Dimensional

Size-dependent mode contributions to the thermal transport of suspended and supported graphene

2019 ◽  
Vol 115 (12) ◽  
pp. 123105 ◽  
Author(s):  
Ji-Hang Zou ◽  
Xin-Tong Xu ◽  
Bing-Yang Cao
Keyword(s):  
Thermal Transport ◽  
Size Dependent

Hotspot Size-Dependent Thermal Boundary Conductance in Nondiffusive Heat Conduction

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Yanbao Ma
Keyword(s):  
Thermal Transport ◽  
Critical Role ◽  
Nonlocal Effects ◽  
Thermal Boundary Conductance ◽  
Interfacial Conditions ◽  
Size Dependent ◽  
Transfer Processes ◽  
Thermal Energy Conversion ◽  
Theoretical Predictions ◽  
The Time Domain

Thermal transport across interfaces can play a critical role in nanosystems for thermal management and thermal energy conversion. Here, we show the dependence of the thermal boundary conductance (G) of the interface between a 70-nm Al transducer and a Si substrate on the size of a laser pump diameter (D) in the time-domain thermoreflectance (TDTR) experiments at room temperature. For D ≥ 30 μm, G approaches to a constant where diffusion dominates the heat transfer processes. When D decreases from 30 μm to 3.65 μm, G decreases from 240 to 170 MW/m2K due to the increasing nonlocal effects from nondiffusive heat transport. This finding is vital to our understanding of the thermal boundary conductance: it depends not only on inherent interfacial conditions but also on external heating conditions, which makes the accurate measurements and theoretical predictions of thermal transport across interfaces in micro/nanosystems more challenging.

Graphene grain size-dependent synthesis of single-crystalline Sb2Te3 nanoplates and the interfacial thermal transport analysis by Raman thermometry

Carbon ◽  
2019 ◽  
Vol 153 ◽  
pp. 164-172 ◽  
Author(s):  
Swati Singh ◽  
Seongkyun Kim ◽  
Wonjae Jeon ◽  
Krishna P. Dhakal ◽  
Jeongyong Kim ◽  
...  
Keyword(s):  
Grain Size ◽  
Thermal Transport ◽  
Single Crystalline ◽  
Size Dependent ◽  
Transport Analysis

scholarly journals Size-Dependent Structural Properties of a High-Nb TiAl Alloy Powder

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 161 ◽  
Author(s):  
Binglin Liu ◽  
Maosong Wang ◽  
Yulei Du ◽  
Jingxiao Li
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Structural Properties ◽  
Structural Changes ◽  
Structural Characteristics ◽  
Nominal Composition ◽  
Induction Melting ◽  
Powder Size ◽  
Size Dependent ◽  
High Temperature Xrd

TiAl-based alloys are promising light weight structural materials for high temperature applications in the field of aerospace. Recently, fabrication technologies starting from powders including powder metallurgy and additive manufacturing have been developed to overcome the difficulties in the processing, machining and shaping of TiAl-based alloys. Spherical alloy powders with different particle size distributions are usually used in these fabrication techniques. The purpose of this study is to reveal the size-dependent structural properties of a high-Nb TiAl powder for these fabrication technologies starting from powders. A high-Nb TiAl pre-alloyed powder with nominal composition of Ti-48Al-2Cr-8Nb (at. %) was prepared by the electrode induction melting gas atomization (EIGA) method. The phase structure and morphology of the as-atomized powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The size-dependent structural changes of the as-atomized powders with different sizes were studied by differential scanning calorimetry (DSC) and in situ high temperature XRD. It was found that with decreasing the powder size, the content of the γ-TiAl phase decreases and the α2-Ti3Al phase increases. The α2-Ti3Al to γ-TiAl phase transformation was found in the temperature range of 600–770 °C. Based on the present work, the structural characteristics of TiAl powders are strongly dependent on their particle size, which should be considered in optimizing the process parameters of TiAl alloys fabricated from powders.

Shape and Internal Structure of Silver Nanoparticles Embedded in Glass

2005 ◽  
Vol 20 (6) ◽  
pp. 1551-1562 ◽  
Author(s):  
H. Hofmeister ◽  
G.L. Tan ◽  
M. Dubiel
Keyword(s):  
Silver Nanoparticles ◽  
Lattice Structure ◽  
Structural Characteristics ◽  
Hexagonal Lattice ◽  
High Resolution Electron Microscopy ◽  
Size Dependent ◽  
Resolution Electron ◽  
Formation Conditions ◽  
Fringe Patterns

The structural characteristics of silver nanoparticles embedded in glass by various routes of fabrication were studied in detail using high-resolution electron microscopy to find out if they are influenced by interaction with the surrounding glass matrix. Besides the formation conditions, the strength of the interaction between metal and glass governs the size-dependent changes of lattice spacings in such nanoparticles. However, determination of these changes is not straightforward because of complicated particle configurations and the interference nature of the lattice imaging technique. Imaging of lattice plane fringes and careful diffractogram analysis allowed the exclusion of any kind of tetragonal lattice distortion or transformation to hexagonal lattice type that may be deduced at first sight. Instead, the formation of twin faults in these nanoparticles turned out to be the essential structural feature and the main source of confusion about the lattice structure observed. The variety of particle forms is comparable to particles supported on oxide carriers. It is composed of single-crystalline particles of nearly cuboctahedron shape, particles containing single twin faults, multiple twinned particles containing parallel twin lamellae, and multiple twinned particles composed of cyclic twinned segments arranged around axes of 5-fold symmetry. The more twin planes involved in the particle composition, the more complicated is the interpretation of lattice spacings and lattice fringe patterns due to superposition of several twin segments.

A Hierarchical Framework for Thermal Modelling of Electronic Devices: From Atoms to Chips

2013 ◽  
Author(s):  
David A. Romero ◽  
Elham Pakseresht ◽  
Daniel Sellan ◽  
Aydin Nabovati ◽  
Cristina Amon
Keyword(s):  
Thermal Transport ◽  
Electronic Devices ◽  
Thermal Conductance ◽  
Logic Gates ◽  
Silicon Films ◽  
Thermal Modelling ◽  
Length Scales ◽  
Energy Carriers ◽  
Size Dependent ◽  
Functional Block

In this work, we provide an overview of a hierarchical computational framework to predict thermal transport in electronic devices through integration of physics-based models at different length scales. Information from atomistic simulations at the smallest length scales are transferred to upper levels of the hierarchy, up to thermal models for the chip. The proposed methodology includes five levels of length scales in electronic devices, namely (i) atomistic level, (ii) thin film and nanowire level, (iii) transistor and logic gate level, (iv) functional block level, and (v) chip level. At the first level of the hierarchy, properties of energy carriers in a semiconductor material (e.g., phonons) are obtained from atomistic level simulations, such as Molecular Dynamics (MD) and Lattice Dynamics (LD) calculations. At the second level, thermal transport in thin silicon films is modelled using a Lattice Boltzmann Method (LBM) for phonons. The outcome of these simulations is a size-dependent thermal conductivity for silicon films. At the third level of the hierarchy, these effective thermal conductivities are used in thermal modelling of logic gates. Detailed structures of different types of logic gates are reconstructed based on different manufacturing technologies (MOSFET and FinFET) at different technology nodes. Since the characteristic sizes of different parts of the logic gates are comparable to the mean free path of energy carriers, we use the size-dependent, effective thermal conductivities that were calculated at lower levels of the hierarchy to build simulation models for the logic gates. Based on these models, we calculate an equivalent thermal conductance for the logic gates, which would then be used in the upper level simulations to determine an equivalent thermal conductance for different functional blocks of the die based on their internal structure and the number and type of logic gates found in each functional block. Overall, the proposed hierarchical model enables us to include the effect of atomistic-level physics into package-level simulations, and thus, have an accurate prediction of thermal transport in an electronic device.

Size-dependent structural characteristics of thin bismuth films

1992 ◽  
Vol 209 (1) ◽  
pp. 32-37 ◽  
Author(s):  
A.A. Ramadan ◽  
A.M. El-Shabiny ◽  
N.Z. El-Sayed
Keyword(s):  
Structural Characteristics ◽  
Size Dependent ◽  
Bismuth Films
Sign in / Sign up

Export Citation Format

Share Document