Annealing Effect on the Thermoelectric Properties of Undoped CoSb3

2006 ◽  
Vol 118 ◽  
pp. 565-570 ◽  
Author(s):  
Il Ho Kim ◽  
Jung Il Lee ◽  
Soon Chul Ur ◽  
Kyung Wook Jang ◽  
Good Sun Choi ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Annealing Effect ◽  
Metallic Behavior ◽  
Arc Melting ◽  
P Type ◽  
Type Conduction

Binary skutterudite CoSb3 compounds were prepared by the arc melting and hot pressing processes and their thermoelectric properties were investigated at 300K-600K. Annealing effect was examined and it was correlated to phase transformation and homogenization. Thermoelectric properties of the arc-melted and hot-pressed CoSb3 were discussed and compared. Undoped CoSb3 prepared by the arc melting showed p-type conduction and metallic behavior at all temperatures examined. However, hot pressed specimens showed n-type conduction, possibly due to Sb evaporation. Thermoelectric properties were remarkably improved by annealing in vacuum and they were closely related to phase transitions.

Thermoelectric Properties of Undoped CoSb3

2004 ◽  
Vol 449-452 ◽  
pp. 917-920 ◽  
Author(s):  
Il Ho Kim ◽  
G.S. Choi ◽  
M.G. Han ◽  
Ji Soon Kim ◽  
Jung Il Lee ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Thermoelectric Properties ◽  
Single Phase ◽  
Arc Melting ◽  
Annealing Effects ◽  
P Type ◽  
Type Conduction ◽  
Semiconducting Behavior

CoSb3 compounds were prepared by the arc melting and their thermoelectric properties were investigated at 300K-600K. Annealing effects were examined and they were correlated to phase transformation and homogenization. Undoped CoSb3 showed p-type conduction and intrinsic semiconducting behavior at all temperatures examined. Thermoelectric properties were changed with constituent phases because α-CoSb2, β-CoSb and Sb are metallic or semimetallic phases while δ-CoSb3 is semiconducting phase. Thermoelectric properties were remarkably improved by annealing in vacuum and they were closely related to phase transitions. Single phase δ-CoSb3 was successfully obtained by annealing at 400°C for 24hrs.

Microstructure and thermoelectric properties of p-type Bi0.5Sb1.5Te3 fabricated by hot pressing

1997 ◽  
pp. 539-543
Author(s):  
Doo-Myun Lee ◽  
Jun-Ho Seo ◽  
Chi-Hwan Lee ◽  
Kyeongsoon Park ◽  
Ichiro Shiota
Keyword(s):  
Thermoelectric Properties ◽  
Hot Pressing ◽  
P Type

scholarly journals Thermoelectric Properties of Nano/microstructured p-Type Bi0.4Sb1.6Te3 Powders Fabricated by Mechanical Alloying and Vacuum Hot Pressing

2013 ◽  
Vol 43 (6) ◽  
pp. 1718-1725 ◽  
Author(s):  
Pee-Yew Lee ◽  
Joey Hao ◽  
Tz-Yuan Chao ◽  
Jing-Yi Huang ◽  
Huey-Lin Hsieh ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Vacuum Hot Pressing ◽  
P Type

Thermoelectric Properties on SixGe1-x Containing Fullerite

2007 ◽  
Vol 280-283 ◽  
pp. 409-412 ◽  
Author(s):  
Gui Ying Xu ◽  
Xiao Feng Wu ◽  
Li Li Zhang ◽  
Chang Chun Ge
Keyword(s):  
Quantum Dot ◽  
Thermoelectric Property ◽  
Thermoelectric Properties ◽  
Thermoelectric Material ◽  
Analytical Method ◽  
Hot Pressing ◽  
Thermoelectric Generator ◽  
Pressing Method ◽  
Higher Temperature ◽  
P Type

SixGe1-x (x = 0.75 for n-type and 0.7 for p-type) is a typical thermoelectric material used at higher temperature as thermoelectric generator. Its property is dependent on the composition. SixGe1-x containing different amount of fullerite added as hollow quantum dot were fabricated by hot-pressing method. The relations among thermoelectric property, the amount of fullerite and the microstructure were investigated by normal measurement and analytical method.

Phase Purity and Thermoelectric Properties of Type-I Clathrates Ba8CuxSiyGe46-x-y (4 ≤ x ≤ 6.5, y = 0 and 5.15 ≤ x ≤ 6.425, 2.05≤ y ≤ 36.9)

2017 ◽  
Vol 1142 ◽  
pp. 37-44
Author(s):  
Yue Dong ◽  
Xin Lin Yan ◽  
Zhao Hui Tang ◽  
Xue Yong Ding ◽  
Xu Dong Sun ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Ball Milling ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Type I ◽  
Phase Purity ◽  
Arc Melting ◽  
Elemental Substitution ◽  
Plasma Sintering ◽  
Spark Plasma

Type-I clathrates have been considered as very promising thermoelectric (TE) materials thus attracting attention widely. Here we report new clathrates Ba8CuxSiyGe46-x-y (4≤ x ≤ 6.5, y = 0 and 5.15 ≤ x ≤ 6.425, 2.05≤ y ≤ 36.9), focusing on their phase purity and TE properties. Our results show that samples prepared by arc melting followed by annealing are multi-phases alloys. The composition of the clathrate phase is also inhomogeneous. This indicates that the kinetic factor dominates the reaction of forming the clathrate phase during element-melting and sample-annealing. We select three compositions in these two series of samples, which have less impurity and better composition homogeneity for the clathrate phase, and the annealed alloys are furthered processed by ball milling (BM) and powder-solidification (either by hot pressing (HP) or by spark plasma sintering (SPS)) for TE properties investigations. The BM and HP/SPS processes can improve the phase purity and homogeneity. The TE measurements show that the Si-substituted samples have better performance than the Ge-based sample, mainly by decreasing the electrical resistivity. This indicates that the elemental substitution may be still an effective way to improve the TE performance of clathrates.

Thermoelectric Properties of P-Type (Bi1−xSbx)2Te3 Fabricated by Mechanical Alloying Process

1997 ◽  
Vol 478 ◽  
Author(s):  
Boo Yang Jung ◽  
Jae Shik Choi ◽  
Tae Sung Oh ◽  
Dow-Bin Hyun
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Alloy Powder ◽  
Figure Of Merit ◽  
Processing Time ◽  
Pressing Temperature ◽  
Acceptor Dopant ◽  
Maximum Value ◽  
P Type

AbstractThermoelectric properties of polycrystalline (Bi1−xSbx)2Te3 (0.75 ≤ x ≤ 0.85), fabricated by mechanical alloying and hot pressing methods, have been investigated. Formation of (Bi0.25Sb0.75)2Te3 alloy powder was completed by mechanical alloying for 5 hours at ball- to-material ratio of 5: 1, and processing time for (Bi1−xSbx)2Te3 formation increased with Sb2Te3 content x. When (Bi0.25Sb0.75)2Te3 was hot pressed at temperatures ranging from 300°C to 550°C for 30 minutes, figure-of-merit increased with hot pressing temperature and maximum value of 2.8 × 10−3/K could be obtained by hot pressing at 550°C. When hot pressed at 550°C, (Bi0.2Sb0.8)2Te3 exhibited figure-of-merit of 2.92 × 10−3/K, which could be improved to 2.97 × 10−3/K with addition of 1 wt% Sb as acceptor dopant.

scholarly journals Study on Enhancing the Thermoelectric Properties of Ti2CrSn Alloys

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1503
Author(s):  
Guangfa Yu ◽  
Shihao Song ◽  
Yanwei Ren ◽  
Jia Guo ◽  
Liqin Yan ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Ground State Band ◽  
Arc Melting ◽  
Maximum Value ◽  
Potential Applications ◽  
State Band ◽  
Elemental Doping ◽  
Microscopic Morphology ◽  
P Type ◽  
Full Heusler

Based on the Hg2CuTi structure, the full-Heusler alloy Ti2CrSn, with a ground state band gap of semiconductor, is a thermoelectric material with potential applications. Through preparing Ti2CrSn1−xAlx (x = 0, 0.05, 0.1, 0.15, 0.2) series bulk materials via arc melting, the effects of the electrical and thermal transport properties of Ti2CrSn series alloys were investigated, and different Al doping on the phase structure, the microscopic morphology, and the thermoelectric properties of Ti2CrSn were examined. The results show that the materials all exhibit characteristics of p-type semiconductors at the temperature range of 323 to 923 K. Al elemental doping can significantly increase the Seebeck coefficient and reduce the thermal conductivity of the materials. Among them, the sample Ti2CrSn0.8Al0.2 obtained a maximum value of 5.03 × 10−3 for the thermoelectric optimal ZT value at 723 K, which is 3.6 times higher than that of Ti2CrSn.

Thermoelectric properties of p-type 25%Bi2Te3+75%Sb2Te3 alloys manufactured by rapid solidification and hot pressing

2002 ◽  
Vol 90 (1-2) ◽  
pp. 42-46 ◽  
Author(s):  
Taek-Soo Kim ◽  
Ik-Soo Kim ◽  
Taek-Kyung Kim ◽  
Soon-Jik Hong ◽  
Byong-Sun Chun
Keyword(s):  
Rapid Solidification ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
P Type
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