Giant room-temperature barocaloric effect at the electronic phase transition in Ni1−xFexS

2020 ◽  
Vol 7 (10) ◽  
pp. 2690-2695
Author(s):  
Jianchao Lin ◽  
Peng Tong ◽  
Xuekai Zhang ◽  
Zichen Wang ◽  
Zhao Zhang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
High Thermal Conductivity ◽  
Electronic Phase ◽  
Electronic Entropy

The electronic entropy enhanced giant barocaloric effect along with high thermal conductivity in hexagonal Ni1−xFexS.

Separation of Internal Strains and Lattice Distortion Caused by Oxygen Impurities in Aluminum Nitride Hot-Pressed Ceramics

1994 ◽  
Vol 38 ◽  
pp. 479-487 ◽  
Author(s):  
O. N. Grigoriev ◽  
S. M. Kushnerenko ◽  
K. A. Plotnikov ◽  
W. Kreher
Keyword(s):  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Integrated Circuit ◽  
Room Temperature ◽  
Lattice Distortion ◽  
High Thermal Conductivity ◽  
Hybrid Integrated Circuit ◽  
Oxygen Contamination ◽  
Internal Strains ◽  
Oxygen Impurities

Recently aluminum nitride (A1N) has been intensively studied as a promising material for production of hybrid integrated circuit substrates because of its high thermal conductivity, high fjexural strength, and nontoxic nature. The estimated theoretical value of its thermal conductivity at room temperature is 320 W/mK, but it is strongly degraded by the introduction of oxygen. The measured values vary from 30 to 260 W/mK, Therefore, in production of this material the reduction of oxygen contamination is of paramount importance.

scholarly journals Long mean free paths of room-temperature THz acoustic phonons in a high thermal conductivity material

2019 ◽  
Vol 100 (9) ◽  
Author(s):  
Ting-Han Chou ◽  
Lucas Lindsay ◽  
Alexei A. Maznev ◽  
Jateen S. Gandhi ◽  
Donna W. Stokes ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
High Thermal Conductivity ◽  
Acoustic Phonons

Vapor grown carbon fiber reinforced aluminum composites with very high thermal conductivity

1995 ◽  
Vol 10 (2) ◽  
pp. 247-250 ◽  
Author(s):  
Jyh-Ming Ting ◽  
Max L. Lake
Keyword(s):  
Thermal Conductivity ◽  
Carbon Fiber ◽  
Thermal Management ◽  
Room Temperature ◽  
Electronic Devices ◽  
High Thermal Conductivity ◽  
Aluminum Metal ◽  
Aluminum Metal Matrix Composite ◽  
New Material ◽  
Very High

The first use of continuous vapor grown carbon fiber (VGCF) as reinforcement in aluminum metal matrix composite (Al MMC) is reported. Al MMC represents a new material for thermal management in high-power, high-density electronic devices. Due to the ultrahigh thermal conductivity of VGCF, 1950 W/m-K at room temperature, VGCF-reinforced Al MMC exhibits excellent thermal conductivity that cannot be achieved by using any other carbon fiber as reinforcement. An unprecedented high thermal conductivity of 642 W/m-K for Al MMC was obtained by using 36.5% of VGCF.

Thermal Conductivity Measurement of Individual Polythiophene Nanofibers With Suspended Micro-Resistance Thermometer Devices

2012 ◽  
Author(s):  
Sally A. McMenamin ◽  
Annie Weathers ◽  
Virendra Singh ◽  
Michael T. Pettes ◽  
Baratunde A. Cola ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Room Temperature ◽  
Defect Density ◽  
Conductivity Measurement ◽  
Polymer Chains ◽  
High Thermal Conductivity ◽  
Resistance Thermometer ◽  
Aligned Nanofibers ◽  
Measured Thermal Conductivity

High thermal conductivity, comparable to that of a metal, has been observed in some stretched polyethylene nanofibers due to a decrease in defect density with the alignment of the polymer chains. Such high thermal conductivity may be useful for thermal management applications such as thermal adhesives made of aligned nanofibers. Polythiophene (Pth) is a conducting polymer that can be synthesized electrochemically as aligned nanofiber forests without the need for stretching individual fibers. Here we report the thermal conductivity of individual suspended Pth nanofibers synthesized electrochemically and measured with the use of a microfabricated device in the temperature range of 80 K to 375 K. The measured thermal conductivity increases with temperature. For three single suspended Pth nanofibers with a diameter on the order of 200 nm, the room temperature value between 0.6 and 0.8 W/m K is about four-fold higher than that reported for Pth thin films and comparable to that reported for binder-filler thermal adhesives.

High Thermal Conductivity Materials

MRS Bulletin ◽  
2001 ◽  
Vol 26 (6) ◽  
pp. 440-444 ◽  
Author(s):  
Koji Watari ◽  
Subhash L. Shinde
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Physical Property ◽  
University Student ◽  
High Thermal Conductivity ◽  
Theoretical Support ◽  
Initial Work ◽  
Fundamental Physical Property ◽  
Good Conductor ◽  
Fundamental Physical

Every university student becomes familiar with the concept of thermal conductivity, a fundamental physical property of materials, through his or her textbooks. Initial work on high thermal conductivity was carried out in 1911 by Eucken, who discovered that diamond was a reasonably good conductor for heat at room temperature. Theoretical support for this discovery was established by Debye in 1914.

scholarly journals Сдвиговые упругие свойства ВТСП керамики в области перехода в сверхпроводящую фазу

2020 ◽  
Vol 90 (6) ◽  
pp. 954
Author(s):  
А.И. Коробов ◽  
А.И. Кокшайский ◽  
Н.В. Ширгина ◽  
Н.И. Одина ◽  
А.А. Агафонов ◽  
...  
Keyword(s):  
Phase Transition ◽  
Elastic Properties ◽  
Room Temperature ◽  
Experimental Studies ◽  
Acoustic Parameter ◽  
Superconducting Transition ◽  
Electronic Phase ◽  
Nonlinear Acoustic Parameter ◽  
Linear And Nonlinear ◽  
Nonlinear Elastic

The results of studies of shear elastic properties of a high-temperature superconducting (HTSC) of YBa2Cu3O7 - x ceramics in the vicinity of the phase transition to the superconducting state at at a temperature of 91.3 K, as well as at room temperature of 293 K are presented. For the first time, a local increase in the shear nonlinear acoustic parameter N was investigated. Experimental studies of the linear and nonlinear elastic properties of HTSC ceramics YBa2Cu3O7 - x in the region of the superconducting transition showed that the electronic phase transition has significant influence on its elastic properties. Based on the results of experimental measurements linear and nonlinear elastic parameters were determined both at room temperature and in the region phase transition temperature.

Room-Temperature Switching Behavior in CNT/Hexadecane Composites

MRS Advances ◽  
2018 ◽  
Vol 3 (54) ◽  
pp. 3213-3220
Author(s):  
Yulong Wu ◽  
Peng Meng ◽  
Quan Zhang ◽  
Zhiyuan Tan ◽  
Guoan Cheng ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Carbon Nanotube ◽  
Room Temperature ◽  
Solid Phase ◽  
Switching Behavior ◽  
Switching Effect ◽  
Automatic Temperature ◽  
Automatic Temperature Control ◽  
Solid Phase Transition

ABSTRACTThe room-temperature switching effect is of great interest for many applications, such as smart buildings, sensors, thermal energy storage and automatic temperature control. In this paper, we report a room-temperature switchable carbon nanotube (CNT)/hexadecane composites. Electrical conductivity, thermal conductivity and permittivity of the CNT/hexadecane composites can be regulated around 18°C and the maximal switching ratio reaches 5 orders of magnitude, 3 times and 106.4, respectively. The switching behavior of composites is caused by rearrangement of the carbon nanotube fillers in hexadecane matrix during liquid-solid phase transition. It is found that surface modification is necessary to improve dispersion stability. Effects of filler properties on switching behaviour are also discussed.

scholarly journals Thermal conductivity of hexagonal BC2P – a first-principles study

RSC Advances ◽  
2020 ◽  
Vol 10 (70) ◽  
pp. 42628-42632
Author(s):  
Rajmohan Muthaiah ◽  
Fatema Tarannum ◽  
Roshan Sameer Annam ◽  
Avinash Singh Nayal ◽  
Swapneel Danayat ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
First Principles ◽  
Room Temperature ◽  
High Thermal Conductivity ◽  
First Principles Calculations ◽  
First Principles Study

In this work, we report a high thermal conductivity (k) of 162 W m−1 K−1 and 52 W m−1 K−1 at room temperature, along the directions perpendicular and parallel to the c-axis, respectively, of bulk hexagonal BC2P (h-BC2P), using first-principles calculations.

Suppressing Ge-vacancies to Achieve High Single-Leg Efficiency in GeTe with Ultra-High Room Temperature Power Factor

2021 ◽  
Author(s):  
Ning Jia ◽  
Cao Jing ◽  
Xian Yi Tan ◽  
Jie Zheng ◽  
Sheauwei Chien ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Power Factor ◽  
High Performance ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Medium Temperature ◽  
Peierls Distortion

GeTe is among the best medium-temperature thermoelectrics. Its high performance originates from band convergence at phase transition and low lattice thermal conductivity due to Peierls distortion. In most works, the...

Magnetic Properties and High Thermal Conductivity of Al2O3 Ceramics Prepared by Spark Plasma Sintering

2013 ◽  
Vol 750-752 ◽  
pp. 512-516 ◽  
Author(s):  
Zhen Hua Jia ◽  
Xin Gui Tang ◽  
Donge Chen ◽  
Jun Bo Wu ◽  
Qiu Xiang Liu
Keyword(s):  
Thermal Conductivity ◽  
Magnetic Properties ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
High Thermal Conductivity ◽  
X Ray ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma

The Al2O3 ceramics with high thermal conductivity prepared the spark plasma sintering (SPS) technology. The structure, image and magnetic properties of the SPS Al2O3 ceramics was characterized by X-ray, field emission scanning electron microscope (FE-SEM) and the vibrating sample magnetometer (VSM) at room temperature. The results shown that the average grain size of the Al2O3 ceramics is about 5~15μm, the thermal conductivity of Al2O3 ceramics up to 24.928 W/(m·K), and the remanent magnetization as higher as 0.00546emu/g and the saturation magnetization as higher as 0.0321 emu/g, respectively. The room-temperature ferromagnetism, which is different from the traditional, possibly originates from the oxygen vacancies.

Sign in / Sign up

Export Citation Format

Share Document