Thermoelectric Properties of Co1-xFexSb3 Prepared by Encapsulated Induction Melting

2007 ◽  
Vol 124-126 ◽  
pp. 939-942 ◽  
Author(s):  
Kwan Ho Park ◽  
Soon Chul Ur ◽  
Il Ho Kim
Keyword(s):  
Heat Treatment ◽  
Thermoelectric Properties ◽  
Single Phase ◽  
Solubility Limit ◽  
Subsequent Heat Treatment ◽  
Optimum Composition ◽  
Induction Melting ◽  
Fe Doping ◽  
Seebeck Coefficients ◽  
P Type

Co1-xFexSb3 skutterudites were synthesized by encapsulated induction melting and their thermoelectric properties were investigated. Single phase δ-CoSb3 was successfully obtained by the subsequent heat treatment at 773K for 24 hours in vacuum. However, δ-CoSb3 was decomposed to FeSb2 and Sb when x≥0.3, which means that the solubility limit of Fe to Co is x<0.3. The positive signs of Seebeck coefficients for all Fe-doped specimens revealed that Fe atoms acted as p-type dopants by substituting Co atoms. Thermoelectric properties were remarkably enhanced by Fe doping and optimum composition was found to be Co0.7Fe0.3Sb3 in this study.

Thermoelectric Properties of Fe-Doped CoSb3 Prepared by Encapsulated Induction Melting and Hot Pressing

2007 ◽  
Vol 534-536 ◽  
pp. 1557-1560 ◽  
Author(s):  
Kwan Ho Park ◽  
Jung Il Lee ◽  
Soon Chul Ur ◽  
Il Ho Kim
Keyword(s):  
Heat Treatment ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Single Phase ◽  
Electron Acceptors ◽  
Subsequent Heat Treatment ◽  
Optimum Composition ◽  
Induction Melting

The encapsulated induction melting and hot pressing were employed to prepare the Fedoped CoSb3 skutterudites and their thermoelectric properties were investigated. Single phase δ- CoSb3 was successfully obtained by the subsequent heat treatment at 773K for 24 hours. Iron atoms acted as electron acceptors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by the appropriate doping. Co0.7Fe0.3Sb3 was found as an optimum composition for best thermoelectric properties in this work.

Thermoelectric Properties of Ni-Doped CoSb3 Prepared by Encapsulated Induction Melting and Hot Pressing

2007 ◽  
Vol 534-536 ◽  
pp. 1561-1564 ◽  
Author(s):  
Mi Jung Kim ◽  
Jung Il Lee ◽  
Soon Chul Ur ◽  
Il Ho Kim
Keyword(s):  
Heat Treatment ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Single Phase ◽  
Subsequent Heat Treatment ◽  
Electron Donors ◽  
Induction Melting ◽  
Doping Effects

Ni-doped CoSb3 was prepared by the encapsulated induction melting and hot pressing, and its doping effects on the thermoelectric properties were investigated. Single phase δ-CoSb3 was successfully obtained by the subsequent heat treatment at 773K for 24 hours. Nickel atoms acted as electron donors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by the appropriate doping.

Thermoelectric Properties of Co1-xNbxSb3 Prepared by Induction Melting

2005 ◽  
Vol 486-487 ◽  
pp. 602-605 ◽  
Author(s):  
J.B. Park ◽  
S.-W. You ◽  
K.W. Cho ◽  
J.I. Lee ◽  
Soon Chul Ur ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermoelectric Properties ◽  
Induction Melting ◽  
Thermoelectric Power Factor ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
High Temperature Maximum ◽  
Higher Temperature ◽  
Nb Doping ◽  
P Type

Induction melting was attempted to prepare the undoped and Nb-doped CoSb3 compounds, and their thermoelectric properties were investigated. Single phase d-CoSb3 was successfully obtained by induction melting and subsequent annealing at 400°C for 2 hours in vacuum. The positive signs of Seebeck coefficients for all the specimens revealed that Nb atoms acted as p-type dopants by substituting Co atoms. Electrical conductivity decreased and then increased withincreasing temperature, indicating mixed behaviors of metallic and semiconducting conductions. Electrical conductivity increased by Nb doping, and it was saturated at high temperature. Maximum value of the thermoelectric power factor was shifted to higher temperature with the increasing amount of Nb doping, mainly originated from the Seebeck coefficient variation.

Electronic Transport Properties of Tin-Filled Cobalt Antimonides

2007 ◽  
Vol 26-28 ◽  
pp. 891-894
Author(s):  
Jae Yong Jung ◽  
Soon Chul Ur ◽  
Il Ho Kim
Keyword(s):  
Heat Treatment ◽  
Transport Properties ◽  
Electronic Transport ◽  
Single Phase ◽  
Induction Melting ◽  
Isothermal Heat Treatment ◽  
Degenerate Semiconductor ◽  
Lattice Contribution ◽  
Electronic Transport Properties ◽  
P Type

The encapsulated induction melting was attempted to prepare the Sn-filled CoSb3 skutterudites and their electronic transport properties were investigated. Single phase δ-CoSb3 was successfully obtained by the subsequent isothermal heat treatment at 823K for 6 days in vacuum. The Sn-filled CoSb3 showed p-type conductivity at 300K to 700K at it is a highly degenerate semiconductor. Lattice contribution was dominant to thermal conductivity and it was considerably reduced by Sn filling in the CoSb3 skutterudite.

Thermoelectric Properties of Co1-xNbxSb3 Prepared by Induction Melting

2005 ◽  
Vol 486-487 ◽  
pp. 554-557
Author(s):  
J.B. Park ◽  
S.-W. You ◽  
K.W. Cho ◽  
J.I. Lee ◽  
Soon Chul Ur ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermoelectric Properties ◽  
Induction Melting ◽  
Thermoelectric Power Factor ◽  
Seebeck Coefficients ◽  
High Temperature Maximum ◽  
Higher Temperature ◽  
Nb Doping ◽  
Increasing Temperature ◽  
P Type

Induction melting was attempted to prepare the undoped and Nb-doped CoSb3 compounds, and their thermoelectric properties were investigated. Single phase d-CoSb3 was successfully obtained by induction melting and subsequent annealing at 400°C for 2 hours in vacuum. The positive signs of Seebeck coefficients for all the specimens revealed that Nb atoms acted as p-type dopants by substituting Co atoms. Electrical conductivity decreased and then increased with increasing temperature, indicating mixed behaviors of metallic and semiconducting conductions. Electrical conductivity increased by Nb doping, and it was saturated at high temperature. Maximum value of the thermoelectric power factor was shifted to higher temperature with the increasing amount of Nb doping, mainly originated from the Seebeck coefficient variation.

Thermoelectric Properties of Skutterudite CoSb3 Prepared by Encapsulated Induction Melting

2007 ◽  
Vol 544-545 ◽  
pp. 921-924
Author(s):  
Soon Chul Ur ◽  
Il Ho Kim
Keyword(s):  
Heat Treatment ◽  
Phase Transitions ◽  
Thermoelectric Properties ◽  
Single Phase ◽  
Induction Melting ◽  
Isothermal Heat Treatment

Encapsulated induction melting was attempted to prepare binary skutterudite CoSb3 and its thermoelectric properties were investigated. Single phase δ-CoSb3 was successfully obtained by the subsequent isothermal heat treatment at 773K-873K for 24 hours in vacuum. Thermoelectric properties were changed with constituent phases because β-CoSb and Sb are metallic/semimetallic phases, while γ-CoSb2 and δ-CoSb3 are semiconducting phases. Thermoelectric properties were remarkably improved by the proper heat treatment and they were closely related to phase transitions.

Enhancing thermoelectric properties of p-type CoSb3 skutterudite by Fe doping

2021 ◽  
Vol 127 ◽  
pp. 105721
Author(s):  
Suchitra Yadav ◽  
Sujeet Chaudhary ◽  
Dinesh K. Pandya
Keyword(s):  
Thermoelectric Properties ◽  
Fe Doping ◽  
P Type

Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

2011 ◽  
Vol 121-126 ◽  
pp. 1526-1529
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Thermoelectric Properties ◽  
Impurity Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

Study on Phases and Thermoelectric Properties of Bulk FexCo4-xSb12 Sintered by MM-SPS

2011 ◽  
Vol 179-180 ◽  
pp. 294-297
Author(s):  
Ke Gao Liu ◽  
Shi Lei
Keyword(s):  
Thermoelectric Properties ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
Semiconducting Materials ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Plasma Sintering ◽  
Electrical Resistivities ◽  
Spark Plasma ◽  
P Type

Bulk FexCo4-xSb12 with x varies from 0.1 to 2.0 were prepared by mechanical milling (MM) and spark plasma sintering (SPS). The phases of the products were characterized by X-ray diffraction (XRD) and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk FexCo4-xSb12 are skutterudite. The electrical resistivities of the products increase first and then decrease. The Seebeck coefficients ( ) are negative when x=0.1 at 100 °C and 200 °C while positive at 300~500 °C. The products with x=0.5~2.0 at 100~500 °C are P type semiconducting materials due to their positive values. The thermal conductivities of most samples increase first and then decrease with x increasing and the maximum is up to 0.39 Wm-1K-1 when x=1.0. The ZT values at 200~500 °C increase first and then decrease with x increasing when x=0.1~1.0 and x=1.0~2.0 respectively and the maximum ZT value is 0.196 when x=1.5 at 400 °C.

First-principles study of the structural and thermoelectric properties of Y-doped α-SrSi2

2022 ◽  
Author(s):  
Masato Yamaguchi ◽  
Daishi Shiojiri ◽  
Tsutomu Iida ◽  
Naomi Hirayama ◽  
Yoji IMAI
Keyword(s):  
Thermoelectric Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Narrow Band ◽  
Hybrid Functional ◽  
Promising Candidate ◽  
Functional Theory ◽  
Seebeck Coefficients ◽  
Increasing Temperature ◽  
P Type

Abstract The narrow-gap semiconductor α-SrSi2 is a promising candidate for low-temperature thermoelectric applications with low environmental load. The only experimental report in which α-SrSi2 is reported to have n-type conductivity is one where it had been doped with yttrium. To further clarify the effects of impurities, theoretical studies are needed. The α-SrSi2 has a very narrow band gap (~13–35 meV), causing difficulties in the accurate calculation of the electronic and thermoelectric properties. In our previous study, we overcame this problem for undoped α-SrSi2 using hybrid functional theory. We used this method in this study to investigate the structures, energetic stabilities, electronic structures, and thermoelectric properties of Y-doped α-SrSi2. The results indicate that substitution at Sr-sites is energetically about two times more stable than that at Si-sites. Furthermore, negative Seebeck coefficients were obtained at low temperatures and reverted to p-type with increasing temperature, which is consistent with the experimental results.

Sign in / Sign up

Export Citation Format

Share Document