Thermal conductivity of ThO2: Effect of point defect disorder

2021 ◽  
Vol 129 (7) ◽  
pp. 075102
Author(s):  
W. Ryan Deskins ◽  
Ahmed Hamed ◽  
Tomohisa Kumagai ◽  
Cody A. Dennett ◽  
Jie Peng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Point Defect ◽  
Defect Disorder

scholarly journals Direct observation of electronic inhomogeneities induced by point defect disorder in manganite films

2010 ◽  
Vol 107 (11) ◽  
pp. 113903 ◽  
Author(s):  
M. Sirena ◽  
A. Zimmers ◽  
N. Haberkorn ◽  
E. Kaul ◽  
L. B. Steren ◽  
...  
Keyword(s):  
Point Defect ◽  
Direct Observation ◽  
Defect Disorder

DEFECT CHARACTERIZATION OF HIGH THERMAL CONDUCTIVITY CaF2 DOPED AlN CERAMICS BY RAMAN SPECTROSCOPY

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3869-3876 ◽  
Author(s):  
HYEON-KEUN LEE ◽  
DO KYUNG KIM
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Raman Spectroscopy ◽  
Point Defect ◽  
Defect Density ◽  
Density Variation ◽  
High Thermal Conductivity ◽  
Boundary Phase ◽  
Oxygen Related Defect

Calcium fluoride additive was used to produce high thermal conductivity AlN ceramics which has no grain boundary phase. Thermal conductivity of AlN is determined by the point defect, represented as oxygen related defect, within the AlN grain. The defect density characterization of high thermal conductivity CaF 2 doped AlN ceramics after heat treatment was conducted by Raman spectroscopy. As measure Raman linewidth broadening, the point defect density variation after heat treatment and corresponding thermal conductivity change was investigated.

scholarly journals Influence of Te Vacancies on the Thermoelectric Properties of n-type Cu0.008Bi2Te2.7-xSe0.3

2020 ◽  
Vol 58 (10) ◽  
pp. 721-727
Author(s):  
Yerim Yang ◽  
TaeWan Kim ◽  
Seokown Hong ◽  
Jiwoo An ◽  
Sang-il Kim
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Point Defect ◽  
Thermoelectric Properties ◽  
Thermal Transport ◽  
Phonon Scattering ◽  
Band Model ◽  
Total Thermal Conductivity ◽  
Thermal Transport Properties ◽  
Callaway Model

In this study, we report the influence of Te vacancy formation on the thermoelectric properties of n-type Cu0.008Bi2Te2.7Se0.3 alloys, including their electronic and thermal transport properties. Te-deficient Cu0.008Bi2Te2.7-xSe0.3 (x = 0, 0.005, 0.01 and 0.02) samples were systematically synthesized and characterized. Regarding electronic transport properties, carrier concentration was increased with Te vacancies, while carrier mobility was maintained. As a result, the electrical conductivity significantly increased while the Seebeck coefficient reduced moderately, thus, the power factor was enhanced from 3.04 mW/mK<sup>2</sup> (pristine) to 3.22 mW/mK<sup>2</sup> (x = 0.02) at 300 K. Further analysis based on a single parabolic band model revealed that the weighted mobility of the conduction band increased, which is favorable for electron transport, as Te vacancies were generated. Regarding thermal transport properties, lattice thermal conductivity decreased with Te vacancies due to additional point defect phonon scattering, however, total thermal conductivity increased due to larger electronic contribution as Te vacancies increased. Analysis using the Debye-Callaway model suggests that the phonon scattering by the Te vacancies is as efficient as the substitution point defect scattering. Consequently, the thermoelectric figure of merit zT increased at all temperatures for x = 0.005 and 0.01. The maximum zT of 0.95 was achieved for Te-deficient Cu0.008Bi2Te2.69Se0.3 (x = 0.01) at 400 K.

Vacancy and anti-site disorder scattering in AgBiSe2 thermoelectrics

2017 ◽  
Vol 46 (12) ◽  
pp. 3906-3914 ◽  
Author(s):  
Felix Böcher ◽  
Sean P. Culver ◽  
Jan Peilstöcker ◽  
Kai S. Weldert ◽  
Wolfgang G. Zeier
Keyword(s):  
Thermal Conductivity ◽  
Point Defect ◽  
Lattice Thermal Conductivity ◽  
Site Disorder ◽  
Disorder Scattering

Ag vacancies in AgBiSe2 influence Ag–Bi anti-site disorder and provide point defect scattering, reducing the lattice thermal conductivity.

The Effects of Material Composition on the Thermal Conductivity of Zeolite MFI

2007 ◽  
Author(s):  
Abraham M. Greenstein ◽  
Yeny C. Hudiono ◽  
Samuel Graham ◽  
Sankar Nair
Keyword(s):  
Thermal Conductivity ◽  
Relaxation Time ◽  
Pore Structure ◽  
Point Defect ◽  
Lattice Dynamics ◽  
Phonon Scattering ◽  
Material Composition ◽  
Boundary Scattering ◽  
Upper Limit ◽  
Effective Suppression

The thermal conductivity of zeolite MFI is modeled for different silicon/aluminum ratios using lattice dynamics and relaxation time theory. The model uses the actual phonon dispersions, Slack’s model for phonon-phonon scattering, a slightly modified form of Klemens’s model for point defect scattering, and a boundary scattering term. Our results strongly suggest that the upper limit of thermal conductivity is defined by boundary-like scattering associated with the pore structure of the material. Below this limit, silicon substitution with aluminum allows effective suppression of the thermal conductivity by point defect scattering and phonon slowing mechanisms.

scholarly journals Correction to Extremely Low Lattice Thermal Conductivity and Point Defect Scattering of Phonons in Ag-doped (SnSe)1–x(SnS)x Compounds

2017 ◽  
Vol 29 (22) ◽  
pp. 9859-9859
Author(s):  
Chan-Chieh Lin ◽  
Lydia Rathnam ◽  
Jae Hyun Yun ◽  
Ho Seong Lee ◽  
Jong-Soo Rhyee
Keyword(s):  
Thermal Conductivity ◽  
Point Defect ◽  
Lattice Thermal Conductivity

Effect of Te substitution on crystal structure and transport properties of AgBiSe2thermoelectric material

2018 ◽  
Vol 47 (8) ◽  
pp. 2575-2580 ◽  
Author(s):  
Y. Goto ◽  
A. Nishida ◽  
H. Nishiate ◽  
M. Murata ◽  
C. H. Lee ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Transport Properties ◽  
Point Defect ◽  
Lattice Thermal Conductivity ◽  
Scattering Model

Reduced lattice thermal conductivity of Te-substituted AgBiSe2was qualitatively described using the point defect scattering model.

scholarly journals Thermal conductivity of the gadolinium calcium silicate apatites: Effect of different point defect types

2011 ◽  
Vol 59 (10) ◽  
pp. 3841-3850 ◽  
Author(s):  
Zhixue Qu ◽  
Taylor D. Sparks ◽  
Wei Pan ◽  
David R. Clarke
Keyword(s):  
Thermal Conductivity ◽  
Point Defect ◽  
Calcium Silicate
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