Electronic Structure and Transport Properties of La2Zr2O7 Pyrochlore from First Principles

2018 ◽  
Vol 281 ◽  
pp. 767-773
Author(s):  
Zheng Li ◽  
Wei Pan
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Electron Concentration ◽  
Boltzmann Transport ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Electronic Thermal Conductivity ◽  
Transport Calculation ◽  
Scattering Time ◽  
High Temperature Electronic

The first principle calculation as well as the Boltzmann transport calculation have been employed to study the high temperature electronic transport properties of pyrochlore La2Zr2O7. Combing constant scattering time approximation and experiment data, the electronic thermal conductivity and electron concentration are calculated as a function of temperature. The electronic thermal conductivity is 2.6×10-4 W/(m.s) at 1270K and 7.2×10-3 W/(m.s) at 1770K. The electron concentration increase rapidly with when the temperature is above 1600K.

Reliability of Thermal Conductivity Measured by Harman Method

1998 ◽  
Vol 545 ◽  
Author(s):  
Y. Shinohara ◽  
Y. Imai ◽  
Y. Isoda ◽  
I. A. Nishida
Keyword(s):  
Thermal Conductivity ◽  
Temperature Difference ◽  
Electron Concentration ◽  
Thermoelectric Materials ◽  
Comparative Method ◽  
Sintered Compact ◽  
Heat Temperature ◽  
Harman Method ◽  
Highly Sensitive ◽  
Standard Value

AbstractThe Harman method was applied to measure thermal conductivity κ of thermoelectric materials, and the reliability of the measured κ was investigated. The quantitative κ requires a highly sensitive technique to measure minute Peltier heat. Temperature difference by Peltier heat pumping was successfully measured by developing the DC method of resistance measurement. κ of n-type Bi2Te3 sintered compact and n-type PbTe boules was measured at 295K by the Harman method. Static comparative method was also applied to obtain the standard value of κ. In the case of Bi2Te3, the κ by the Harman method agreed well with the standard value. In the case of PbTe in the electron concentration ne range <5 × 1024/m3, the κ almost agreed with the standard value. However, PbTe in the ne range ≥1 × 1025/m3 showed a larger κ than the standard value. The Harman method has an error to give the larger κ for the material with a large carrier component κ, of κ This error is due to the fast conduction of Peltier heat by the carrier. The reliable κ can be measured for the material with a small κ,.

High-temperature thermoelectric properties of n-type BayNixCo4−xSb12

2001 ◽  
Vol 16 (12) ◽  
pp. 3343-3346 ◽  
Author(s):  
X. F. Tang ◽  
L. M. Zhang ◽  
R. Z. Yuan ◽  
L. D. Chen ◽  
T. Goto ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Electron Concentration ◽  
Lattice Thermal Conductivity ◽  
Filling Fraction ◽  
Ni Content ◽  
Increasing Temperature

Effects of Ba filling fraction and Ni content on the thermoelectric properties of n-type BayNixCo4−xSb12 (x = 0−0.1, y = 0−0.4) were investigated at temperature range of 300 to 900 K. Thermal conductivity decreased with increasing Ba filling fraction and temperature. When y was fixed at 0.3, thermal conductivity decreased with increasing Ni content and reached a minimum value at about x = 0.05. Lattice thermal conductivity decreased with increasing Ni content, monotonously (y ≤ 0.1). Electron concentration and electrical conductivity increased with increasing Ba filling fraction and Ni content. Seebeck coefficient increased with increasing temperature and decreased with increasing Ba filling fraction and Ni content. The maximum ZT value of 1.25 was obtained at about 900 K for n-type Ba0.3Ni0.05Co3.95Sb12.

scholarly journals High Thermal Conductivity of Gallium Nitride (GaN) Crystals Grown by HVPE Process

2007 ◽  
Vol 48 (10) ◽  
pp. 2782-2786 ◽  
Author(s):  
Hiroyuki Shibata ◽  
Yoshio Waseda ◽  
Hiromichi Ohta ◽  
Kazumasa Kiyomi ◽  
Kenji Shimoyama ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Gallium Nitride ◽  
High Thermal Conductivity

Accurate dependence of gallium nitride thermal conductivity on dislocation density

2006 ◽  
Vol 89 (9) ◽  
pp. 092123 ◽  
Author(s):  
C. Mion ◽  
J. F. Muth ◽  
E. A. Preble ◽  
D. Hanser
Keyword(s):  
Thermal Conductivity ◽  
Gallium Nitride ◽  
Dislocation Density

scholarly journals Thermal Conductivity of Wurtzite Zinc-Oxide from First-Principles Lattice Dynamics – a Comparative Study with Gallium Nitride

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xufei Wu ◽  
Jonghoon Lee ◽  
Vikas Varshney ◽  
Jennifer L. Wohlwend ◽  
Ajit K. Roy ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Gallium Nitride ◽  
Comparative Study ◽  
First Principles ◽  
Lattice Dynamics

High thermal conductivity and thermal boundary conductance of homoepitaxially grown gallium nitride (GaN) thin films

2021 ◽  
Vol 5 (10) ◽  
Author(s):  
Yee Rui Koh ◽  
Md Shafkat Bin Hoque ◽  
Habib Ahmad ◽  
David H. Olson ◽  
Zeyu Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Gallium Nitride ◽  
High Thermal Conductivity ◽  
Thermal Boundary Conductance
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