Thermal Characterization of Nanowire Array in a-Al2O3 Matrix

2001 ◽  
Vol 703 ◽  
Author(s):  
Diana-Andra Borca-Tasciuc ◽  
Gang Chen ◽  
Yu-Ming Lin ◽  
Oded Rabin ◽  
Mildred S. Dresselhaus ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Figure Of Merit ◽  
Average Length ◽  
Nanowire Array ◽  
Thermal Characterization ◽  
Thermoelectric Figure ◽  
Conduction Model ◽  
Effective Thermal Diffusivity ◽  
Nanowires Array

ABSTRACTThermal properties characterization of Bi nanowires is critical in order to validate the predicted enhancement of their thermoelectric figure-of-merit. In this paper we report the effective thermal diffusivity of Bi nanowires array embedded in a-Al2O3 (alumina) template. The composite material consists of 85% alumina and approximately 15% Bi nanowires with a diameter of 40 nm and an average length of 40 [.proportional]m. Measurements are performed along the nanowire axis. A thermal wave is produced at the front side of the sample and it is monitored at the backside through a fast thermoelectric effect. A one-dimensional heat conduction model is used to extract the thermal diffusivity.

Thermal Diffusivity Characterization of Bi2Te3 Nanowires Array Inside Amorphous Alumina Template

2002 ◽  
Author(s):  
Diana-Andra Borca-Tasciuc ◽  
Gang Chen ◽  
Marisol S. Martin-Gonzales ◽  
Amy L. Prieto ◽  
Angelica Stacy ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Figure Of Merit ◽  
Large Contribution ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Alumina Template ◽  
Amorphous Alumina ◽  
Low Dimensional

In the recent years there has been an increasing interest in low-dimensional thermoelectric materials such as superlattices, quantum dots and nanowires [1,2,3]. An enhancement in thermoelectric figure-of-merit, Z=σα2/k, where α is the Seebeck coefficient, σ is electrical conductivity, and k is the thermal conductivity, is predicted due to increased density of states near Fermi level [4]. A large contribution to the enhancement of thermoelectric figure-of-merit in low-dimensional systems may come from thermal conductivity reduction due to increased scattering of heat carriers from interfaces. In this light, we are interested in thermal properties of Bi2Te3 nanowires and carried out thermal diffusivity characterization of these nanowires embedded in an amorphous alumina template.

scholarly journals THERMAL CHARACTERIZATION OF MULTI-WALL CARBON NANOTUBE BUNDLES BASED ON PULSED LASER-ASSISTED THERMAL RELAXATION

2008 ◽  
Vol 01 (01) ◽  
pp. 71-76 ◽  
Author(s):  
JIAQI GUO ◽  
XINWEI WANG ◽  
DAVID B. GEOHEGAN ◽  
GYULA ERES
Keyword(s):  
Carbon Nanotube ◽  
Thermal Diffusivity ◽  
Thermal Relaxation ◽  
Thermal Characterization ◽  
Nanosecond Laser ◽  
One Dimensional ◽  
Nanotube Bundles ◽  
The Wire ◽  
Multi Wall Carbon Nanotube

A novel transient technique is developed to measure the thermal diffusivity of one-dimensional microscale wires. In this technique, a pulsed nanosecond laser is used to quickly heat the wire. After laser heating, the wire temperature decays slowly. Such temperature decay is sensed and used to determine the thermal diffusivity of the wire. A 25.4 μm thin Pt wire is characterized to verify this technique. The thermal diffusivity of multi-wall carbon nanotube bundles is measured. Based on the measurement result and the inside structure, the thermal diffusivity of individual carbon nanotubes is estimated.

Characterization of Thin-film Thermoelectric Micro-modules using Transient Harman ZT Measurement and Near-IR Thermoreflectance

2007 ◽  
Vol 1044 ◽  
Author(s):  
Rajeev Singh ◽  
James Christofferson ◽  
Zhixi Bian ◽  
Joachim Nurnus ◽  
Axel Schubert ◽  
...  
Keyword(s):  
Thin Film ◽  
Heat Load ◽  
Figure Of Merit ◽  
Near Infrared ◽  
Device Performance ◽  
Metal Contacts ◽  
Thermoelectric Figure ◽  
Near Ir ◽  
Harman Technique

AbstractWe characterize several thin film thermoelectric micro-modules composed of 20 µm-thick elements and designed for cooling applications to identify factors that may limit device performance. Thermoelectric figure-of-merit measurements using the transient Harman technique are compared with maximum cooling data under no heat load. Correlation between the two measurements depending on the location of the parasitic joule heating in the module is analyzed. Near-infrared thermoreflectance is used to examine temperature non-uniformity in the module. The temperature distribution on the metal contacts due to the Peltier and Joule effects is obtained non-destructively through the silicon substrate of an active module.

Thermal Characterization of Low Thermal Diffusivity Glasses

1992 ◽  
pp. 217-220
Author(s):  
M. Bertolotti ◽  
R. Li Voti ◽  
G. Liakhou ◽  
C. Sibilia ◽  
A. Montenero ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Thermal Characterization

Structural and Thermal Characterization of Polymorphic Er2Si2O7

2012 ◽  
Vol 510-511 ◽  
pp. 255-260
Author(s):  
Ashari Maqsood
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Transport Properties ◽  
Temperature Region ◽  
Thermal Characterization ◽  
Plane Source ◽  
Transient Plane Source ◽  
Transient Plane Source Technique ◽  
Made In

The first measurement of thermal transport properties on the polycrystalline D-Er2Si2O7have been made in the temperature range 77-300K. Both the thermal conductivity and the thermal diffusivity follow modified Euckens law in this temperature region. The Transient Plane Source technique (TPS) has been used to measure thermal conductivity and thermal diffusivity simultaneously.

scholarly journals Photoacoustic thermal characterization of low thermal diffusivity thin films

2021 ◽  
Vol 22 ◽  
pp. 100246
Author(s):  
K. Herrmann ◽  
N.W. Pech-May ◽  
M. Retsch
Keyword(s):  
Thin Films ◽  
Thermal Diffusivity ◽  
Thermal Characterization

Characterization of Heat Diffusion Properties of Rubberized Two-Layer Systems Using Open Photoacoustic Cell Spectroscopy

2017 ◽  
Vol 72 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Thiago V. Moreno ◽  
Nilson E. Souza Filho ◽  
Andressa Novatski ◽  
Luis C. Malacarne ◽  
Gustavo S. Dias ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Thermal Resistance ◽  
Aluminum Foil ◽  
Heat Diffusion ◽  
Photoacoustic Cell ◽  
Effective Thermal Diffusivity ◽  
Open Photoacoustic Cell ◽  
Precise Tool ◽  
Transfer Problems

We applied the open photoacoustic cell method operating at high frequency as an efficient and highly precise tool for the measurement of thermal properties of rubberized two-layer systems. The heat-coupling between the two layers is treated using the analogy between thermal and electrical resistances widely used in heat transfer problems. The thermal resistance between the two layers is considered effective and the problem is decoupled for each layer. Measurements are performed in two-layer samples of aluminum foil coated with layers of rubberized paint with different thicknesses. Thermal diffusivity and thermal conductivity are determined for the paint. The results are retrieved from the thermal resistance model assuming the effective thermal diffusivity of the composite material.

scholarly journals Si-Based Materials for Thermoelectric Applications

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1943 ◽  
Author(s):  
Sora-at Tanusilp ◽  
Ken Kurosaki
Keyword(s):  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Melt Spinning ◽  
Production Costs ◽  
Synthesis And Characterization ◽  
Thermoelectric Figure ◽  
Metal Silicides ◽  
High Power Factor ◽  
Low Toxicity

Si-based thermoelectric materials have attracted attention in recent decades with their advantages of low toxicity, low production costs, and high stability. Here, we report recent achievements on the synthesis and characterization of Si-based thermoelectric materials. In the first part, we show that bulk Si synthesized through a natural nanostructuring method exhibits an exceptionally high thermoelectric figure of merit zT value of 0.6 at 1050 K. In the second part, we show the synthesis and characterization of nanocomposites of Si and metal silicides including CrSi2, CoSi2, TiSi2, and VSi2. These are synthesized by the rapid-solidification melt-spinning (MS) technique. Through MS, we confirm that silicide precipitates are dispersed homogenously in the Si matrix with desired nanoscale sizes. In the final part, we show a promising new metal silicide of YbSi2 for thermoelectrics, which exhibits an exceptionally high power factor at room temperature.

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