LnPdSb and Ln3Au3Sb4: New Thermoelectric Materials

1998 ◽  
Vol 545 ◽  
Author(s):  
K. Mastronardi ◽  
D. Young ◽  
C.-C. Wang ◽  
A. P. Ramirez ◽  
P. Khalifah ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Heusler Alloys ◽  
Disordered Materials ◽  
Cubic Symmetry ◽  
Seebeck Coefficients ◽  
Band Structure Calculations ◽  
P Type ◽  
Structure Calculations

AbstractThe thermoelectric properties near ambient temperature of half-Heusler alloys based on HoPdSb, DyPdSb, and ErPdSb are reported. The Seebeck coefficients are between 60 and 250 μV/K. The resistivities range between 0.6 and 20 mΩcm, and the majority carriers are p-type. Thermal conductivities are smallest in intentionally disordered materials. The highest ambient temperature ZT obtained is 0.06. Band structure calculations are presented, and are compared to those for ZrNiSn. It is suggested that half-Heusler alloys with 18 electrons per formula unit may represent a large class of thermoelectric materials. The thermoelectric properties of another family of cubic symmetry antimonides, based on Ho3Au3Sb4 and Sm3Au3Sb4, are also reported.

scholarly journals Thermoelectric properties of the Zintl phases Yb5M2Sb6(M = Al, Ga, In)

2015 ◽  
Vol 44 (15) ◽  
pp. 6767-6774 ◽  
Author(s):  
Umut Aydemir ◽  
Alex Zevalkink ◽  
Alim Ormeci ◽  
Heng Wang ◽  
Saneyuki Ohno ◽  
...  
Keyword(s):  
Band Structure ◽  
Thermoelectric Properties ◽  
Zintl Phases ◽  
Seebeck Coefficients ◽  
Band Structure Calculations ◽  
P Type ◽  
Structure Calculations

Zintl compounds of Yb5M2Sb6(M = Al, Ga, and In) exhibit semimetallic properties with high p-type carrier concentrations, low resistivities and low Seebeck coefficients in agreement with our band structure calculations.

The first-principle study of the electronic, optical and thermoelectric properties of XTiO3 (X = Ca, Sr and Ba) compounds

2016 ◽  
Vol 30 (20) ◽  
pp. 1650141 ◽  
Author(s):  
A. A. Mubarak
Keyword(s):  
Band Structure ◽  
Thermoelectric Properties ◽  
Optical Parameters ◽  
Lattice Constants ◽  
Energy Bandgap ◽  
Band Structure Calculations ◽  
Type Semiconductor ◽  
Oxide Perovskite ◽  
P Type ◽  
Structure Calculations

The FP-LAPW method is utilized to investigate the elastic, optoelectronic and thermoelectric properties of [Formula: see text] [Formula: see text] and [Formula: see text] within the GGA. The calculated lattice constants and bulk modulus are found in agreement with previous studies. The present oxide–perovskite compounds are characterized as elastically stable and anisotropic. [Formula: see text] and [Formula: see text] are categorized as ductile compounds, whereas the [Formula: see text] compound is in the critical region between ductile and brittle. The DOS and the band structure calculations reveal indirect [Formula: see text]–[Formula: see text] energy bandgap for the present compounds. The hydrostatic pressure increases the energy bandgap and the width of the valence band. The character of the band structure does not change due to this pressure. The optical parameters are calculated in different radiation regions. Beneficial optics applications are predicted as revealed from the optical spectra. The transport properties are applied as a function of the variable temperatures or carrier concentration. It is found that the compounds under study are classified as a p-type semiconductor. The majority charge carriers responsible for conduction in these calculated compounds are holes rather than electrons.

Thermal Conductivity and Thermoelectric Properties of Novel Rare Earth Boron-Rich Cluster Compounds; Discovery of first undoped n-type B12 icosahedral compound

2005 ◽  
Vol 886 ◽  
Author(s):  
Takao Mori
Keyword(s):  
Thermal Conductivity ◽  
Rare Earth ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Homologous Series ◽  
Cluster Compounds ◽  
Rich Cluster ◽  
Boron Cluster ◽  
Seebeck Coefficients ◽  
P Type

ABSTRACTNovel rare earth boron icosahedral compounds are investigated as potential high temperature thermoelectric materials. REB50-type compounds and a homologous series of RE-B-C(N) compounds were synthesized and the thermal conductivity and thermoelectric properties measured. Seebeck coefficients in excess of 200 μV/K are observed at temperatures above 1000 K for the REB50-type compounds. Strikingly, n-type behavior was observed for REB22C2N and REB17CN. Up to now, non-doped B12 icosahedral compounds like boron carbide have all been p-type. The discovery of an n-type compound is extremely important in terms of the potential development of this class of compounds as viable thermoelectric materials. Low thermal conductivities of κ < 0.03 W/cm/K at room temperature was observed for these rare earth boron cluster compounds. In comparison among the homologous series in which there are rare earth and B6 octahedra layers separated by an increasing number of B12 icosahedra layers, we observe that the thermal conductivity actually increases as the number of boron cluster layers increases. We find that the rare earth B12 icosahedral cluster compounds in which RE atoms occupy voids among the clusters generally appear to have lower thermal conductivity than boron cluster compounds which do not contain RE atoms.

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.

Fabrication of Bi-Te Based Thermoelectric Semiconductors by Using Hybrid Powders

2005 ◽  
Vol 297-300 ◽  
pp. 875-880
Author(s):  
Cheol Ho Lim ◽  
Ki Tae Kim ◽  
Yong Hwan Kim ◽  
Dong Choul Cho ◽  
Young Sup Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Single Crystals ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Bending Strength ◽  
Mixing Ratio ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

P-type Bi0.5Sb1.5Te3 compounds doped with 3wt% Te were fabricated by spark plasma sintering and their mechanical and thermoelectric properties were investigated. The sintered compounds with the bending strength of more than 50MPa and the figure-of-merit 2.9×10-3/K were obtained by controlling the mixing ratio of large powders (PL) and small powders (PS). Compared with the conventionally prepared single crystal thermoelectric materials, the bending strength was increased up to more than three times and the figure-of-merit Z was similar those of single crystals. It is expected that the mechanical properties could be improved by using hybrid powders without degradation of thermoelectric properties.

Synthesis and Thermoelectric Properties of Undoped Half-Heusler Zr-Co-Sb Alloy Processed by Mechanically Alloying and Hot Pressing

2011 ◽  
Vol 695 ◽  
pp. 69-72
Author(s):  
Il Ho Kim ◽  
Joon Chul Kwon ◽  
Young Geun Lee ◽  
Sung Lim Ryu ◽  
Man Soon Yoon ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Hot Pressing ◽  
Heusler Alloys ◽  
Processing Route ◽  
Mechanically Alloyed ◽  
Fundamental Study ◽  
Vacuum Hot Pressing ◽  
Fine Grain

Half-Heusler alloys are one of the potential thermoelectric materials for medium to high temperature range application. As a part of fundamental study to establish processing route and to observe thermoelectric properties in undoped state, ZrCoSb was selected, processed and evaluated. In an attempt to produce a half-Heusler thermoelectric materials having ultra fine grain structures, ZrCoSb was synthesized by mechanical alloying of stoichiometric elemental powder compositions, and consolidated by vacuum hot pressing. Phase transformations during mechanical alloying and hot consolidation were investigated using XRD, SEM and EDS. Single-phase, half-Heusler was successfully produced by vacuum hot pressing using as-milled powders without subsequent annealing. Thermoelectric properties as functions of temperature were evaluated in terms of Seebeek coefficient, electrical conductivity, thermal conductivity and the figure of merit for the hot pressed specimens. Mechanically alloyed half-Heusler phase, ZrCoSb, appeared to have a great potential as a thermoelectric materials in this study.

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.

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.

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