Synthesis, Crystal Structure and Thermoelectric Properties of β-K2Bi8Se13 Solid Solutions

ABSTRACTSolid solution series of the type K2Bi8-xSbxSe13, K2-xRbxBi8Se13 as well as K2Bi8Se13-xSx were prepared and the distribution of the atoms (Bi/Sb, K/Rb and Se/S) on different crystallographic sites, the band gaps and their thermoelectric properties were studied. The distribution Se/S appears to be more uniform than the distribution of the Sb and Rb atoms in the β-K2Bi8Se13 structure that shows preference in specific sites in the lattice. Band gap is mainly affected by Sb and S substitution. Seebeck coefficient measurements showed n-type character for of all Se/S members. In the Bi/Sb series an enhancement of p-type character was observed. The thermoelectric performance as well as preliminary high temperature measurements suggest the potential of these materials for high temperature applications.

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Thermoelectric Properties of Sn2+-Substituted CuFeO2 Delafossite-Oxide

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.802.17 ◽

2013 ◽

Vol 802 ◽

pp. 17-21 ◽

Cited By ~ 2

Author(s):

Chesta Ruttanapun ◽

Phumin Jindajitawat ◽

Warawoot Thowladda ◽

Worakarn Neeyakorn ◽

Chanchana Thanachayanont ◽

...

Keyword(s):

Crystal Structure ◽

High Temperature ◽

Solid State ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Positive Sign ◽

Prediction Formula ◽

Mixed Valency ◽

Maximum Power Factor ◽

P Type

This study aims to investigate the effect of the Sn2+-substituted into the CuFeO2delafossite on thermoelectric properties in the Sn content of x = 0.03, 0.05. The CuFe1−xSnxO2samples were synthesized by solid state reaction. The crystal structure was characterized by XRD, TGA, XPS and the thermoelectric properties were measured in the range of 300 to 960 K. The Seebeck coefficient display positive sign in all temperature range and the XPS show the stable Sn+2state as confirming the Sn-doped CuFeO2playing p-type conductor. The Sn2+-substituted supports the mixed valency Fe3+/Fe4+state in transition octahedral oxide of FeO6layer enhancing Seebeck coefficient. The high Seebeck are appeared in content of x=0.03 which are 280 to 340 µV/K in the range of 300 to 800 K. The experimental Seebeck corresponds to the prediction formula at high temperature. Totally, the maximum Power Factor is 2.30×10−4W/mK2occurring in the CuFe0.95Sn0.05O2at 860 K which is higher than that value of the undoped-CuFeO2in 4 times. These support that the Sn-substituted CuFeO2delafossite enhancing thermoelectric properties.

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Thermoelectric Properties of K2Bi8Se13−xSx Solid Solutions

MRS Proceedings ◽

10.1557/proc-0886-f08-02 ◽

2005 ◽

Vol 886 ◽

Cited By ~ 1

Author(s):

Theodora Kyratsi ◽

Sangeeta Lal ◽

Tim Hogan ◽

Mercouri G. Kanatzidis

Keyword(s):

Thermal Conductivity ◽

Solid Solution ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Lattice Thermal Conductivity ◽

The Other ◽

Solid Solution Series ◽

Type Character ◽

Derivatives Of

AbstractDerivatives of β-K2Bi8Se13 are an interesting series of materials for thermoelectric investigations due to their very low thermal conductivity and highly anisotropic electrical properties. Up to now substitutions on the Bi and alkali metal sites have been studied in order to tune the thermoelectric properties. In this work, the thermoelectric properties of the sulfur-substituted K2Bi8Se13−xSx (0<x<13) are presented with respect to Seebeck coefficient, the electrical and thermal conductivity as a function of temperature. Seebeck coefficient measurements showed the n-type character of all members while electrical conductivity shows higher values compare to the other solid solution series of the same type. The lattice thermal conductivity is affected due to the Se/S disorder. The temperature dependence of the figure-of-merit ZT shows that these materials have potential for high temperatures applications with promising thermoelectric performance.

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The solid solution series Tl(V1−xCrx)5Se8: crystal structure, magnetic and thermoelectric properties

Journal of Materials Chemistry C ◽

10.1039/c5tc01766a ◽

2015 ◽

Vol 3 (40) ◽

pp. 10509-10517 ◽

Cited By ~ 7

Author(s):

Stefan Maier ◽

Robin Lefèvre ◽

Xinsong Lin ◽

Raghavendra Nunna ◽

David Berthebaud ◽

...

Keyword(s):

Crystal Structure ◽

Solid Solution ◽

Thermoelectric Properties ◽

Solid Solution Series ◽

Single Crystalline ◽

Solution Series

The crystal structure of single crystalline members of the solid solution series Tl(V1−xCrx)5Se8 (x = 0–1 and Δx = 0.2) was determined and the magnetic and thermoelectric properties of bulk TlV5Se8 were investigated.

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THERMOELECTRIC PROPERTIES OF Ti-DOPED SiC/TiCx COMPOSITE SYNTHESIZED BY TPPP METHOD

Modern Physics Letters B ◽

10.1142/s0217984900000197 ◽

2000 ◽

Vol 14 (04) ◽

pp. 131-138 ◽

Cited By ~ 3

Author(s):

HONG CHEN ◽

YUZHE YIN ◽

YUANJIN HE

Keyword(s):

Solid Solution ◽

High Temperature ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Room Temperature ◽

Lattice Parameter ◽

Interstitial Impurities ◽

Plastic Phase ◽

Phase Process

To improve thermoelectric properties, we attempt to dope Ti into SiC-based composite by transient plastic phase process (TPPP) method. The final result is composed of the functional phase SiC and the reinforcement phases TiC x and TiSi 2. The process of doping is the diffusion of Ti in TiC x solid–solution into SiC grain at high temperature. When the initial SiC is α-type of 5 μm size, the Seebeck coefficient S is less than 10 μV/K at room temperature. SEM photograph shows the reason being that doping is very weak. We change the initial SiC to the β-type of 90 nm size to aid doping. It is observed that S can be significantly improved to 46.3 μV/K at room temperature. When the temperature rises, the improvement is even greater. Measurements of the lattice parameter of β- SiC show that the parameter parallel to the Si–C layer is almost unchanged and the parameter perpendicular to the Si–C layer increases by about 0.48%, which demonstrated that Ti has been successfully doped into the SiC grain and exists as interstitial impurities.

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Synthesis and High Temperature Thermoelectric Properties of Alkaline-Earth Metal Hexaborides MB6 (M=Ca, Sr, Ba)

MRS Proceedings ◽

10.1557/proc-793-s8.11 ◽

2003 ◽

Vol 793 ◽

Cited By ~ 4

Author(s):

Masatoshi Takeda ◽

Yosuke Kurita ◽

Keisuke Yokoyama ◽

Takahiro Miura ◽

Tsuneo Suzuki ◽

...

Keyword(s):

Electrical Conductivity ◽

High Temperature ◽

Seebeck Coefficient ◽

Carrier Concentration ◽

Thermoelectric Properties ◽

Alkaline Earth ◽

Earth Metal ◽

Thermoelectric Device ◽

Alloying Effect ◽

P Type

ABSTRACTPolycrystalline alkaline-earth hexaborides (MB6: M =Ca, Sr, Ba) were synthesized and their thermoelectric and transport properties were examined to discuss their possibility as high temperature thermoelectric materials. Hall measurements showed that carrier concentration of the BaB6 was the highest among the three hexaborides and that of CaB6 was the lowest. Substitution of part of the alkaline earth metals with one of the others changed the carrier concentration of the hexaboride. As the carrier concentration increased, Seebeck coefficient increased and electrical conductivity decreased. These results suggest that the thermoelectric properties of the divalent hexaborides depend largely on the carrier concentration, and optimum carrier concentration which gives maximum power factor was estimated to be approximately 2x1026 m−3. Consequently, such a substitution enables us to control Seebeck coefficient and electrical conductivity of the hexaborides, and will also be effective to reduce the lattice heat conduction due to the alloying effect. A thermoelectric device was fabricated using SrB6 and boron carbide thin films as n-type and p-type elements, respectively. To the best of our knowledge, this is the first demonstration of a thermoelectric device composed of only boron-rich solids.

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Effect of Cobalt-Substitution on the Structure and Thermoelectric Properties of Chimney-Ladder Solid Solution (Mn1-xCox)Siγ (γ~ 1.7)

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.74.22 ◽

2010 ◽

Vol 74 ◽

pp. 22-25 ◽

Cited By ~ 6

Author(s):

Yuzuru Miyazaki ◽

Yoshitsugu Saito ◽

Kei Hayashi ◽

Kunio Yubuta ◽

Tsuyoshi Kajitani

Keyword(s):

Crystal Structure ◽

Solid Solution ◽

Thermoelectric Properties ◽

Valence Electron ◽

Annealing Process ◽

Axis Ratio ◽

Cobalt Substitution ◽

Valence Electrons ◽

Unknown Factor ◽

P Type

A partially cobalt-substituted solid solution of Nowotny chimney-ladder phase, (Mn1-xCox)Si􀀂, has been prepared using a tetra-arc-type furnace and a subsequent annealing process. The compounds consist of two tetragonal subsystems of [Mn1-xCox] and [Si], with an irrational c-axis ratio 􀀂 = cMn/cSi ~ 1.7. The crystal structure and thermoelectric properties of (Mn1-xCox)Si􀀂 solid solution were compared with those of the Fe-substituted solid solution, (Mn1-xFex)Si􀀂. In the case of Co-series, extra valence electrons are introduced relative to Fe-series, since the valence electron count is 3d74s2 for Co but 3d64s2 for Fe, respectively. It was naturally expected that the Feand Co-substituted MnSi􀀁 becomes n-type conductor from the p-type one at x > 0.23(5) and x > 0.06(1), respectively. Experimentally, the Fe-substituted samples become n-type at x > 0.28 but it is not the case for the Co-substituted ones. It is thus evident that there is an unknown factor which controls the thermoelectric properties of Co-substituted samples.

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Investigation of Thermoelectric Properties of P-Type GaN Thin Films

MRS Proceedings ◽

10.1557/opl.2015.706 ◽

2015 ◽

Vol 1774 ◽

pp. 13-18

Author(s):

Bahadir Kucukgok ◽

Babar Hussain ◽

Chuanle Zhou ◽

Ian T. Ferguson ◽

Na Lu

Keyword(s):

High Temperature ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Room Temperature ◽

Mechanical Stability ◽

Gradient Methods ◽

Chemical Vapor ◽

High Seebeck Coefficient ◽

P Type ◽

Bipolar Conduction

ABSTRACTGaN and its alloys are promising candidates for high temperature thermoelectric (TE) materials due to their high Seebeck coefficient and high thermal and mechanical stability. Moreover, these materials can overcome the toxicity concern of current Te-based TE materials, such as Bi2Te3 and PbTe. These materials have recently shown a higher Seebeck coefficient than that of SiGe in high temperature region because their large bandgap characteristic eliminates the bipolar conduction. In this study, we report the room temperature thermoelectric properties of p-type Mg doped GaN, grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrate with various carrier concentrations. Undoped and n-type GaN are also incorporated with p-type GaN films to make comparison. The structural, optical, electrical, and thermal properties of the samples were examined by X-ray diffraction, photoluminescence, van der Pauw hall-effect, and thermal gradient methods, respectively. The Seebeck coefficient ranging from 710-900µV/K at room temperature of Mg: GaN were observed, which further indicated their potential TE applications.

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