Thermal Conductivity Reduction by Fluctuation of the Filling Fraction in Filled Cobalt Antimonide Skutterudite Thermoelectrics

2018 ◽  
Vol 1 (11) ◽  
pp. 6181-6189 ◽  
Author(s):  
F. Serrano-Sánchez ◽  
J. Prado-Gonjal ◽  
N. M. Nemes ◽  
N. Biskup ◽  
O. J. Dura ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Filling Fraction ◽  
Cobalt Antimonide

Effects of Ce filling fraction and Fe content on the thermoelectric properties of Co-rich CeyFexCo4−xSb12

2001 ◽  
Vol 16 (3) ◽  
pp. 837-843 ◽  
Author(s):  
Xinfeng Tang ◽  
Lidong Chen ◽  
Takashi Goto ◽  
Toshio Hirai
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Single Phase ◽  
Lattice Thermal Conductivity ◽  
Hole Concentration ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Filling Fraction ◽  
Fe Content

Single-phase filled skutterudite compounds, CeyFexCo4−xSb12 (x = 0 to 3.0, y = 0 to 0.74), were synthesized by a melting method. The effects of Fe content and Ce filling fraction on the thermoelectric properties of CeyFexCo4−xSb12 were investigated. The lattice thermal conductivity of Ce-saturated CeyFexCo4−xSb12, y being at the maximum corresponding to x, decreased with increasing Fe content (x) and reached its minimum at about x = 1.5. When x was 1.5, lattice thermal conductivity decreased with increasing Ce filling fraction till y = 0.3 and then began to increase after reaching the minimum at y = 0.3. Hole concentration and electrical conductivity of Cey Fe1.5Co2.5Sb12 decreased with increasing Ce filling fraction. The Seebeck coefficient increased with increasing Ce filling fraction. The greatest dimensionless thermoelectric figure of merit T value of 1.1 was obtained at 750 K for the composition of Ce0.28Fe1.52Co2.48Sb12.

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.

Study on Thermal Conductivity of Filled Silicone Rubber

2012 ◽  
Vol 501 ◽  
pp. 88-93 ◽  
Author(s):  
Lian Xiang Ma ◽  
Jin Xu ◽  
Yan He ◽  
Jia Na Ke
Keyword(s):  
Thermal Conductivity ◽  
Silicone Rubber ◽  
Coupling Agent ◽  
Filling Fraction ◽  
Filler Size ◽  
Conductive Fillers ◽  
Conductive Silicone Rubber ◽  
Sic Particle

The heat conductive silicone rubber is prepared with methy1 viny1 silicone rubber as basic gum and SiCp (SiC particle), SiCp/SiCw (SiC whisker), graphite as heat conductive fillers. The effects of filler amount, filler shape, filler size and coupling agent on the thermal conductivity of silicone rubber have been studied in this article. The result shows that when the filling amount is increasing, the thermal conductivity of composite silicone rubber will increase too. There is no evident change for thermal conductivity with the small filling fraction, while the filling amount reaches a certain value, the thermal conductivity of composite increases obviously. Moreover, the thermal conductivity added with coupling agent (KH-602) is higher than that of composite without coupling agent addition.

scholarly journals Substantial thermal conductivity reduction in mischmetal skutterudites MmxCo4Sb12 prepared under high-pressure conditions, due to uneven distribution of the rare-earth elements

2019 ◽  
Vol 7 (14) ◽  
pp. 4124-4131 ◽  
Author(s):  
J. Gainza ◽  
F. Serrano-Sánchez ◽  
J. Prado-Gonjal ◽  
N. M. Nemes ◽  
N. Biskup ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Lattice Thermal Conductivity ◽  
Low Cost ◽  
Uneven Distribution ◽  
Filling Fraction ◽  
The Rare Earth

Low-cost n-type Mischmetal-filled CoSb3 skutterudites with elemental filling-fraction separation, prepared at high pressure, exhibit markedly low lattice thermal conductivity.

scholarly journals Low thermal conductivity in La-filled cobalt antimonide skutterudites with an inhomogeneous filling factor prepared under high-pressure conditions

2018 ◽  
Vol 6 (1) ◽  
pp. 118-126 ◽  
Author(s):  
F. Serrano-Sánchez ◽  
J. Prado-Gonjal ◽  
N. M. Nemes ◽  
N. Biskup ◽  
M. Varela ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Filling Factor ◽  
Lattice Thermal Conductivity ◽  
Low Thermal Conductivity ◽  
Cobalt Antimonide ◽  
Filled Skutterudites

La-filled skutterudites with an inhomogeneous filling factor synthesized by high pressure exhibit a remarkably low lattice thermal conductivity.

scholarly journals Structural Properties and Thermoelectric Performance of the Double-Filled Skutterudite (Sm,Gd)y(FexNi1-x)4Sb12

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2451 ◽  
Author(s):  
Cristina Artini ◽  
Riccardo Carlini ◽  
Roberto Spotorno ◽  
Fainan Failamani ◽  
Takao Mori ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Mass Difference ◽  
Small Mass ◽  
Thermoelectric Performance ◽  
Filling Fraction ◽  
Filled Skutterudite ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Ionic Size

The structural and thermoelectric properties of the filled skutterudite (Sm,Gd)y(FexNi1-x)4Sb12 were investigated and critically compared to the ones in the Sm-containing system with the aim of unravelling the effect of double filling on filling fraction and thermal conductivity. Several samples (x = 0.50–0.90 and y = 0.15–0.48) were prepared by melting-sintering, and two of them were densified by spark plasma sintering in order to study their thermoelectric features. The crystallographic study enables the recognition of the role of the filler size in ruling the filling fraction and the compositional location of the p/n crossover: It has been found that the former lowers and the latter moves toward lower x values with the reduction of the filler ionic size, as a consequence of the progressively weaker interaction of the filler with the Sb12 cavity. The analysis of thermoelectric properties indicates that, despite the Sm3+/Gd3+ small mass difference, the contemporary presence of these ions in the 2a site significantly affects the thermal conductivity of both p- and n-compositions. This occurs by reducing its value with respect to the Sm-filled compound at each temperature considered, and making the overall thermoelectric performance of the system comparable to several multi-filled (Fe, Ni)-based skutterudites described in the literature.

Numerical Investigation of Thermal Conductivity of Particle Dispersive Composites Based on Fractal Method

2012 ◽  
Vol 616-618 ◽  
pp. 1808-1812
Author(s):  
Xiao Chuan Li ◽  
Xiang Yong Huang
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Polymer Matrix ◽  
Volume Fraction ◽  
Polymer Matrix Composites ◽  
Fractal Theory ◽  
High Heat ◽  
Matrix Composites ◽  
Filling Fraction ◽  
High Heat Transfer

Heat conduction performance of particle dispersive composites has been numerically investigated by using Finite volume method (FVM) and fractal theory. The effects of the thermal conductivity of particle and polymer matrix, the volume fraction of conductive particle, the dispersion and reunion form of particles on the effective thermal conductivity of composites are analyzed in detail. Results from the research indicate that thermal conductivities of composites will increase nonlinearly along with the increase of filling fraction of particles. Keeping the filling fraction constant, the dispersion and reunion form and direction of particles has significant effect on heat conduction performance of composite. Simple use of high thermal conductivity particles has limited effect on thermal performance of composites. Enhancing the contacts of particle in the direction of heat exchange and forming high heat transfer channels are the main and economical ways to improve heat conduction performance of particulate filled polymer matrix composites.

How cerium filling fraction influences thermal factors and magnetism in CeyFe4-xNixSb12.

2000 ◽  
Vol 626 ◽  
Author(s):  
L. Chapon ◽  
D. Ravot ◽  
J.C. Tedenac ◽  
F. Bouree-Vigneron
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Theoretical Calculations ◽  
Filling Fraction ◽  
Rare Earth Atom ◽  
Filled Skutterudites ◽  
Order Of Magnitude ◽  
Mass Fluctuation

Since few years, cerium filled and partially filled skutterudites are intensively studied because they show a wide variety of fundamental and applied properties. One of them consists in high values of thermal factors for rare earth atom in antimony skutterudites [1,2]. Slack suggests [3,4] a incoherent rattling of this ion in the oversized cage “Sb12” surrounding the cerium which affects highly the phonon motion and thus lowers the lattice thermal conductivity (kl). As a rule, the lattice thermal conductivity is decreased by a factor of 5 or greater by filling entirely the voids of the binary filled skutterudites with rare earth atoms [5]. Besides, kl decreases for partially filled compounds in respect with totally filled ones [6,7]. Mass fluctuation mechanism between cerium atom and vacancy is obviously involved as the origin of this last reduction. On that purpose, theoretical calculations [7] demonstrate that the reduction belonging to mass fluctuation mechanism is an order of magnitude lower than the measured decrease. As the mass fluctuation added to the “rattling” on the cerium site is not sufficient to explain such low values of thermal conductivity, another phonon scattering mechanism must exist. In order to find another mechanism we present the influence of the filling fraction of cerium on thermal factors and the temperature dependence of this factor for a partially filled compound.

Transport Properties of Partially-Filled CeyCo4Sb12

1997 ◽  
Vol 478 ◽  
Author(s):  
C. Uher ◽  
B. Chen ◽  
S. Hu ◽  
D.T. Morelli ◽  
G.P. Meisner
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Magnetic Moment ◽  
Strong Influence ◽  
Lattice Thermal Conductivity ◽  
Filling Fraction ◽  
Figures Of Merit ◽  
Trivalent Cerium ◽  
Filled Skutterudites ◽  
P Type

AbstractWe have investigated the magnetic and transport properties of CeyCo4Sb12 filled skutterudites with the filling fraction y ≤ 0.1. These compounds are n-type materials that develop a magnetic moment upon the presence of trivalent cerium. Cerium has a strong influence on all transport properties and even in small amounts it drastically reduces the lattice thermal conductivity. The resulting figures of merit are comparable to the values established previously for the p-type filled skutterudites.

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