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.

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.

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 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.

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.

Thermoelectric Properties of Tl2Te-Sb2Te3 Pseudo-Binary System

2005 ◽  
Vol 886 ◽  
Author(s):  
Ken Kurisaki ◽  
Keita Goto ◽  
Atsuko Kosuga ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Binary System ◽  
Thermoelectric Properties ◽  
Room Temperature ◽  
State Of The Art ◽  
Electrical Performance ◽  
Low Thermal Conductivity ◽  
Maximum Value ◽  
P Type ◽  
Type Conduction

ABSTRACTPolycrystalline-sintered samples of thallium based substances, (Tl2Te)100−x(Sb2Te3)x (x= 0, 1, 5, 10), were prepared by melting Tl2Te and Sb2Te3 ingots followed by annealing in sealed quartz ampoules. The thermoelectric properties were measured from room temperature to around 600 K. The values of the Seebeck coefficient of all samples are positive, indicating a p-type conduction characteristic. The maximum value of the power factor is 6.53×10−4 Wm−1K−2 at 591 K obtained for x= 10 (Tl9SbTe6), which is about one order lower than those of state-of-the-art thermoelectric materials. All samples indicate an extremely low thermal conductivity, for example that of Tl2Te is approximately 0.35 Wm−1K−1 from room temperature to around 600 K. Although the electrical performance of the samples is not so good, the ZT value is relatively high due to the extremely low thermal conductivity. The maximum ZT value is 0.42 at 591 K obtained for Tl9SbTe6.

Enhanced thermoelectric properties of the hole-doped Bi2−xKxSr2Co2Oy ceramics

2015 ◽  
Vol 29 (28) ◽  
pp. 1550192 ◽  
Author(s):  
Feng Gao ◽  
Qinglin He ◽  
Ruijuan Cao ◽  
Fang Wu ◽  
Xing Hu ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Solid State Reaction Method ◽  
Undoped Sample ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Element Doping ◽  
P Type ◽  
Remarkable Reduction

In this paper, the influence of K element doping on the thermoelectric properties of the [Formula: see text] (x = 0.00, 0.05, 0.10, 0.15, and 0.20) samples prepared by the solid-state reaction method were investigated from 333 K to 973 K. It was shown that due to the p-type K doping the electrical resistivity of the doped sample can be reduced remarkably as compared with the undoped sample, especially for the optimum doped sample [Formula: see text]. The Seebeck coefficients of the K doped samples have only a slight decrease as compared with the undoped sample. As a result of the remarkable reduction of the electrical resistivity the power factor of the doped sample have a significant improvement. The thermal conductivity of the samples is depressed due to the defects caused by K doping. As an overall result, the dimensionless figure of merit (ZT) of the [Formula: see text] sample reaches a maximum value of 0.3 at 973 K, being 93% higher than that of the undoped sample.

Thermoelectric properties of Ru and In substituted misfit-layered Ca3Co4O9

2013 ◽  
Vol 1543 ◽  
pp. 83-92 ◽  
Author(s):  
Gesine Saucke ◽  
Sascha Populoh ◽  
Nina Vogel-Schäuble ◽  
Leyre Sagarna ◽  
Kailash Mogare ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Low Temperatures ◽  
Figure Of Merit ◽  
Reaction Route ◽  
Promising Strategy ◽  
Maximum Value ◽  
Solid State Reaction Route ◽  
P Type

ABSTRACTAs an approach to improve the thermoelectric properties of the polycrystalline Ca3Co4O9 misfit-layered oxide, substitutions of Co2+…4+ with the heavier cations Ru3+/4+ and In3+ were tested. Polycrystalline samples Ca3Co4-xRuxO9 and Ca3Co4-xInxO9 (0 < x < 0.21) were prepared via a solid-state-reaction route. For each sample the crystal structure was analyzed and a complete thermoelectric characterization was done within a temperature range of 300 K < T < 1125 K.Both substitution strategies resulted in a significant decrease of the thermal conductivity (κ). For the In3+-substituted samples the decrease of the Seebeck coefficient (α) balanced the κ reduction so that no overall enhancement of the figure of merit (ZT) was found. The Ru3+/4+ substitution reduced the p-type carrier concentration and thus increases the electrical resistivity (ρel), while α became larger at low temperatures. Despite the reduction of the power factor, a small enhancement in ZT was observed in the case of x = 0.1 Ru substitution, due to the strong κ reduction. Considering the observed preferred orientation of the Ru-substituted crystallites, a maximum value of ZT = 0.14 perpendicular to the pressing direction is found at T = 1125 K, indicating that Ru substitution is a promising strategy for a further ZT improvement.

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.

THERMOELECTRIC PROPERTIES OF MANGANESE-DOPED p-TYPE SKUTTERUDITES CeyFe4-xMnxSb12

2013 ◽  
Vol 06 (05) ◽  
pp. 1340003 ◽  
Author(s):  
PENGFEI QIU ◽  
XUN SHI ◽  
RUIHENG LIU ◽  
YUTING QIU ◽  
SHUN WAN ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermoelectric Properties ◽  
Hole Concentration ◽  
Mn Doping ◽  
Maximum Value ◽  
The Matrix ◽  
Filled Skutterudites ◽  
P Type ◽  
Mn Doped ◽  
Thermal Conductivities

R y Fe 4 Sb 12-based filled skutterudites have been studied extensively as p-type legs used in high-temperature thermoelectric generator. One approach to further improve their thermoelectric performance is to optimize the overhigh hole concentration in R y Fe 4 Sb 12 skutterudite. In this study, we used element Mn doped on the skutterudite framework and systemically investigated the effects of Mn on the filler filling fractions, crystal structures, and high-temperature thermoelectric properties in Ce y Fe 4-x Mn x Sb 12. It is found that the Mn doping limit at Fe sites is around 0.15. Mn doping slightly enhances Ce filling fractions because Mn acts as an electron acceptor and its doping could push more electron donator Ce into the voids of skutterudites. Although Mn has one valence electron less than Fe , the excessive electrons donated by Ce fillers can completely compensate the holes generated by Mn and reduce the material's hole concentration, leading to a much reduced electrical conductivity and electrical thermal conductivity. Since the lattice thermal conductivities of Mn -doped samples are almost unchanged as compared with that of the matrix, the total thermal conductivities are obviously decreased. Meanwhile, high power factors are maintained in Mn -doped samples because of the enhanced Seebeck coefficient as well as the undegraded carrier mobility. As a combined effect, the figure of merit in Mn -doped samples is much improved in the whole temperature range. Sample CeFe 3.85 Mn 0.15 Sb 12 exhibits a maximum value of 0.98 at 800 K among all the samples investigated in this work.

Thermoelectric Properties of Bulk FeSb2 and the Composite of FeSb2 and CoSb3 Prepared by Sintering

2011 ◽  
Vol 71-78 ◽  
pp. 3741-3744
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Electric Resistivity ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

For investigating the thermoelectric properties, bulk FeSb2and the composite of CoSb3:FeSb2=7:3 was prepared via sintering. 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, bulk FeSb2and the composite of CoSb3:FeSb2=7:3 are P-type semiconductor materials. The electric resistivity of bulk FeSb2sample increases with temperature rising while that of the composite (CoSb3:FeSb2=7:3) decreases with temperature rising. The Seebeck coefficient of the composite (CoSb3:FeSb2=7:3) is evidently higher than that of bulk FeSb2. The thermal conductivities of the composite (CoSb3:FeSb2=7:3) are relatively lower than those of bulk FeSb2. TheZTvalues of bulk FeSb2sample are lower than those of the composite (CoSb3:FeSb2=7:3), that of the later increases with temperature rising at 100~500°C, the maximum value is up to 0.1647.

Sign in / Sign up

Export Citation Format

Share Document