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.

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.

scholarly journals Theoretical Study on Thermoelectric Properties and Doping Regulation of Mg3X2 (X = As, Sb, Bi)

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 971
Author(s):  
Xiaofang Wang ◽  
Yong Lu ◽  
Ziyu Hu ◽  
Xiaohong Shao
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Theoretical Study ◽  
Phonon Dispersion ◽  
First Principle ◽  
Combined Method ◽  
Figures Of Merit ◽  
P Type

For searching both high-performances and better fits for near-room temperature thermoelectric materials, we here carried out a theoretical study on thermoelectric properties and doping regulation of Mg3X2 (X = As, Sb, Bi) by the combined method of first principle calculations and semi-classical Boltzmann theory. The thermoelectric properties of n-type Mg3As2, Mg3Sb2, and Mg3Bi2 were studied, and it was found that the dimensionless figures of merit, zT, are 2.58, 1.38, 0.34, and the p-type ones are 1.39, 0.64, 0.32, respectively. Furthermore, we calculated the lattice thermal conductivity of doped structures and screened out the structures with a relatively low formation energy to study the phonon dispersion and thermal conductivity in Mg3X2 (X = As, Sb, Bi). Finally, high thermoelectric zT and ultralow thermal conductivity of these doped structures was discussed.

scholarly journals Strongly reduced lattice thermal conductivity in Sn-doped rare-earth (M) filled skutterudites MxCo4Sb12−ySny, promoted by Sb–Sn disordering and phase segregation

RSC Advances ◽  
2021 ◽  
Vol 11 (42) ◽  
pp. 26421-26431
Author(s):  
J. Gainza ◽  
F. Serrano-Sánchez ◽  
N. M. Nemes ◽  
O. J. Dura ◽  
J. L. Martínez ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Carrier Density ◽  
Lattice Thermal Conductivity ◽  
Phase Segregation ◽  
Intrinsic Disorder ◽  
Filling Fraction ◽  
Filled Skutterudites ◽  
Sn Substitution ◽  
The Way

Three effects act as phonon scatterers: rattling of M at 8a cages, phase segregation, and intrinsic disorder introduced by Sn substitution, resulting in minimum k values. High filling fraction in Sn-doped phases pave the way to tune the carrier density in skutterudites.

Synthesis and Lattice Thermal Conductivity of Double Atoms Filling p-Type CamCenFexCo4-xSb12 Compounds

2007 ◽  
Vol 336-338 ◽  
pp. 838-841
Author(s):  
Han Li ◽  
Xin Feng Tang ◽  
Tao Xiang Liu ◽  
Chen Song ◽  
Qing Jie Zhang
Keyword(s):  
Thermal Conductivity ◽  
Rietveld Refinement ◽  
Single Phase ◽  
Lattice Thermal Conductivity ◽  
Melting Reaction ◽  
Filling Fraction ◽  
Reaction Method ◽  
P Type

Single-phase double atoms filling skutterudite compounds were synthesized by using melting reaction method. The effects of double atoms filling on the structure and lattice thermal conductivity of skutterudite compounds were investigated. The results of Rietveld refinement indicate that CamCenFexCo4-xSb12 compounds possess skutterudite structure and the Sb-icosahedron voids have been partially filled with filling atoms. With the same filling fraction, the lattice thermal conductivity of CamCenFexCo4-xSb12 is smaller than that of CamFexCo4-xSb12 and CenFexCo4-xSb12, furthermore, when the total filling fraction (m+n) is about 0.3 and respective filling fraction of Ca and Ce are approximately equal, the lattice thermal conductivity is the least.

Partial filling of skutterudites: Optimization for thermoelectric applications

2005 ◽  
Vol 20 (12) ◽  
pp. 3234-3237 ◽  
Author(s):  
G.S. Nolas ◽  
G. Fowler
Keyword(s):  
Thermal Conductivity ◽  
Electrical Properties ◽  
Transport Properties ◽  
Figure Of Merit ◽  
Large Range ◽  
Debye Model ◽  
Figures Of Merit ◽  
Partial Filling ◽  
Filled Skutterudites

Over the last ten years there has been substantial experimental and theoretical effort in understanding the transport properties of filled skutterudite compounds to optimize their thermoelectric properties. One such approach involves partially filling the voids in attempting to optimize the electrical properties while minimizing the thermal conductivity. We illustrate the importance of this approach by plotting and comparing the figure of merit of CoSb3 over a large range of carrier concentrations and thermal conductivity values. The thermal conductivity of partially filled skutterudites AxCo4Sb12, where A = La, Eu, and Yb, is analyzed using the Debye model to correlate the data with the type of filler atom in evaluating the role of the filler in affecting the thermal conductivity. Partial void filling has resulted in relatively high thermoelectric figures of merit at moderately high temperatures.

scholarly journals Formation of Dense Pore Structure by Te Addition in Bi0.5Sb1.5Te3: An Approach to Minimize Lattice Thermal Conductivity

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Syed Waqar Hasan ◽  
Hyeona Mun ◽  
Sang Il Kim ◽  
Jung Young Cho ◽  
Jong Wook Roh ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Structure ◽  
Transport Properties ◽  
Power Factor ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Synergetic Effects ◽  
Spark Plasma ◽  
P Type

We herein report the electronic and thermal transport properties of p-type Bi0.5Sb1.5Te3polycrystalline bulks with dense pore structure. Dense pore structure was fabricated by vaporization of residual Te during the pressureless annealing of spark plasma sintered bulks of Te coated Bi0.5Sb1.5Te3powders. The lattice thermal conductivity was effectively reduced to the value of 0.35 W m−1 K−1at 300 K mainly due to the phonon scattering by pores, while the power factor was not significantly affected. An enhancedZTof 1.24 at 300 K was obtained in spark plasma sintered and annealed bulks of 3 wt.% Te coated Bi0.5Sb1.5Te3by these synergetic effects.

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.

scholarly journals Study of anisotropic thermal conductivity in textured thermoelectric alloys by Raman spectroscopy

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24456-24465
Author(s):  
Rapaka S. C. Bose ◽  
K. Ramesh
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Transport Properties ◽  
Thermal Transport ◽  
Layered Crystal ◽  
Layered Crystal Structure ◽  
Thermal Transport Properties ◽  
Anisotropic Thermal Conductivity ◽  
P Type

Polycrystalline p-type Sb1.5Bi0.5Te3 (SBT) and n-type Bi2Te2.7Se0.3 (BTS) compounds possessing layered crystal structure show anisotropic electronic and thermal transport properties.

Thermoelectric Properties of K2Bi8−xSbxSe13Solid Solutions and Se Doping

2001 ◽  
Vol 691 ◽  
Author(s):  
Theodora Kyratsi ◽  
Jeffrey S. Dyck ◽  
Wei Chen ◽  
Duck-Young Chung ◽  
Ctirad Uher ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Charge Transport ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Se Doping ◽  
Mass Fluctuation ◽  
Thermal Conductivities

ABSTRACTOur efforts to improve the thermoelectric properties of β-K2Bi8Se13, led to systematic studies of solid solutions of the type β-K2Bi8−xSbxSe13. The charge transport properties and thermal conductivities were studied for selected members of the series. Lattice thermal conductivity decreases due to the mass fluctuation generated in the lattice by the mixed occupation of Sb and Bi atoms. Se excess as a dopant was found to increase the figure-of merit of the solid solutions.

A High Thermoelectric Performance ZT in p-Type LaSe2 Crystal

2021 ◽  
Vol 871 ◽  
pp. 203-207
Author(s):  
Jian Liu
Keyword(s):  
Thermal Conductivity ◽  
Power Factor ◽  
High Power ◽  
Density Functional ◽  
Lattice Thermal Conductivity ◽  
Phonon Transport ◽  
Thermoelectric Performance ◽  
Boltzmann Transport ◽  
High Power Factor ◽  
P Type

In this work, we use first principles DFT calculations, anharmonic phonon scatter theory and Boltzmann transport method, to predict a comprehensive study on the thermoelectric properties as electronic and phonon transport of layered LaSe2 crystal. The flat-and-dispersive type band structure of LaSe2 crystal offers a high power factor. In the other hand, low lattice thermal conductivity is revealed in LaSe2 semiconductor, combined with its high power factor, the LaSe2 crystal is considered a promising thermoelectric material. It is demonstrated that p-type LaSe2 could be optimized to exhibit outstanding thermoelectric performance with a maximum ZT value of 1.41 at 1100K. Explored by density functional theory calculations, the high ZT value is due to its high Seebeck coefficient S, high electrical conductivity, and low lattice thermal conductivity .

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