Thermoelectric Materials with Skutterudite Structure: New Results
Skutterudite semiconductors possess attractive transport properties and have a good potential for.
Skutterudite Structure↗
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Thermoelectric devices based on materials with filled skutterudite structures
A class of thermoelectric compounds based on the skutterudite structure with heavy filling atoms in the empty octants and substituting transition metals and main-group atoms. High Seebeck coefficients and low thermal conductivities are achieved in combination with large electrical conductivities in these filled skutterudites for large ZT values. Substituting and filling methods are disclosed to synthesize skutterudite compositions with desired thermoelectric properties. A melting and/or sintering process in combination with powder metallurgy techniques is used to fabricate these new materials.
Fleurial, Jean-Pierre↗
Thermoelectric materials with filled skutterudite structure for thermoelectric devices
A class of thermoelectric compounds based on the skutterudite structure with heavy filling atoms in the empty octants and substituting transition metals and main-group atoms. High Seebeck coefficients and low thermal conductivities are achieved in combination with large electrical conductivities in these filled skutterudites for large ZT values. Substituting and filling methods are disclosed to synthesize skutterudite compositions with desired thermoelectric properties. A melting and/or sintering process in combination with powder metallurgy techniques is used to fabricate these new materials.
Fleurial, Jean-Pierre↗
Thermoelectric materials with filled skutterudite structure for thermoelectric devices
A class of thermoelectric compounds based on the skutterudite structure with heavy filling atoms in the empty octants and substituting transition metals and main-group atoms. High Seebeck coefficients and low thermal conductivities are achieved in combination with large electrical conductivities in these filled skutterudites for large ZT values. Substituting and filling methods are disclosed to synthesize skutterudite compositions with desired thermoelectric properties. A melting and/or sintering process in combination with powder metallurgy techniques is used to fabricate these new materials.
Fleurial, Jean-Pierre↗
Thermoelectric Materials With the Skutterudite Structure: New Results
New experimental findings on semiconductors with the relatively complex 32 atom unit cell skutterudite crystal structure show that these materials possess attractive transport properties and have a good potential for achieving ZT values larger than for state-of- the-art thermoelectric materials. An overview of recent results is provided, and current approaches to experimentally achieving high ZT in skutterudite materials are discussed.
thermoelectrics skutterudites↗
Solid Solutions Formation: Improving the Thermoelectric Properties of Skutterudites
Materials with skutterudite structure have been known for a long time. Some of them are semiconductors. A typical skutterudite is CoSb(sub 3) and its thermoelectric properties were partially studied in the 1960's. Recently, it has been discovered that many skutterudite compounds are thermoelectrics with promising future.
skutterudite skutterudite structure thermoelectric↗
Bridgman-solution Crystal Growth and Characterization of Skutterudite Compounds CoSb(sub 3) and RhSb(sub 3)
Several semiconducting compounds with the skutterudite structure are attractive materials for thermoelectric and electronic applications.
semiconducting compounds skutterudite structure tw↗
Preparation and Characterization of the Skutterudite-Related Phase Ru0.5Pd0.5 Sb3
A new skutterudite phase Ru0.5Pd0.5 Sb3 was prepared. It adds to the many materials with the skutterudite structure that have shown a good potential for thermoelectric applications. Single- phase polycrystalline samples were prepared and characterized by x-ray analysis, electron probe microanalysis, density, sound velocity, thermal expansion coefficient, and differential thermal analysis measurements.
ternary↗
Skutterudites: a New Class of Promising Thermoelectric Materials
Based on literature data and experimental findings at JPL, semiconductors with the skutterudite structure TPn(sub 3) (where T is a transition metal element such as Co, Rh, Ir, Ni and Pd, and Pn is a pnicogen element such as P, As and Sb) possess attractive characteristics and show a good potential for high ZT values. the high degree of covalency results in high mobility and low electrical resistivity values while a relatively complex 32-atom unit cell results in a reasonably low thermal conductivity.
skutterudites thermoelectric material↗
Thermoelectric materials development
A systematic search for advanced thermoelectric materials was initiated at JPL several years ago to evaluate candidate materials which includes consideration of the following property attributes: (1) semiconducting properties; (2) large Seebeck coefficient; (3) high carrier mobility and high electrical conductivity; (4) low lattice thermal conductivity; and (5) chemical stability and low vapor pressure. Through this candidate screening process, JPL identified several families of materials as promising candidates for improved thermoelectric materials including the skutterudite family. As part of an ongoing effort to develop skutterudite materials with lower thermal conductivity values, several solid solutions and filled skutterudite materials were investigated under the effort sponsored by DOE. The efforts have primarily focused on: (1) study of existence and properties of solid solutions between the binary compounds CoSb3 and IrSb3, and RuSb2Te, and (2) CeFe(4-x)Sb12 based filled compositions. For the solid solutions, the lattice thermal conductivity reduction was expected to be reduced by the introduction of the Te and Ru atoms while in the case of CeFe(4-x)Ru(x)Sb12 based filled compositions. For the solid solutions, the lattice thermal conductivity reduction was expected to be reduced by the introduction of the Te and Ru atoms while in the case of CeFe(4-x)Ru(x)Sb12 filled compositions, the reduction would be caused by the rattling of Ce atoms located in the empty voids of the skutterudite structure and the substitution of Fe for Ru. The details of the sample preparation and characterization of their thermoelectric properties are reported in this report.
Fleurial, J. P.↗
Preparation and Thermoelectric Properties of the Skutterudite-Related Phase Ru(0.5)Pd(0.5)Sb3
A new skutterudite phase Ru(0.5)Pd(0.5)Sb3 was prepared. This new phase adds to a large number of already known materials with the skutterudite structure which have shown good potential for thermoelectric applications. Single phase, polycrystalline samples were prepared and characterized by x-ray analysis, electron probe microanalysis, density, sound velocity, thermal-expansion coefficient, and differential thermal analysis measurements. Ru(0.5)Pd(0.5)Sb3 has a cubic lattice, space group Im3 (T(sup 5, sub h)), with a = 9.298 A and decomposes at about 920 K. The Seebeck coefficient, the electrical resistivity, the Hall effect, and the thermal conductivity were measured on hot-pressed samples over a wide range of temperatures. Preliminary results show that Ru(0.5)Pd(0.5)Sb3 behaves as a heavily doped semiconductor with an estimated band gap of about 0.6 eV. The lattice thermal conductivity of Ru(0.5)Pd(0.5)Sb3 is substantially lower than that of the binary isostructural compounds CoSb3 and IrSb3. The unusually low thermal conductivity might be explained by additional hole and charge transfer phonon scattering in this material. The potential of this material for thermoelectric applications is discussed.
Caillat, T.↗
Bridgman-Solution Crystal Growth and Characterization of the Skutterudite Compounds CoSb3 and
Compounds with the skutterudite structure have recently been identified as advanced.
Bridgman-Solution↗
Process in the Search for Advanced Thermoelectric Materials for Terrestrial Applications at the Jet
The thermoelectric properties of several materials with the skutterudite structure have been.
Advanced Thermoelectric Materials↗
Thermoelectric Skutterudite Compositions and Methods for Producing the Same
Compositions related to skutterudite-based thermoelectric materials are disclosed. Such compositions can result in materials that have enhanced ZT values relative to one or more bulk materials from which the compositions are derived. Thermoelectric materials such as n-type and p-type skutterudites with high thermoelectric figures-of-merit can include materials with filler atoms and/or materials formed by compacting particles (e.g., nanoparticles) into a material with a plurality of grains each having a portion having a skutterudite-based structure. Methods of forming thermoelectric skutterudites, which can include the use of hot press processes to consolidate particles, are also disclosed. The particles to be consolidated can be derived from (e.g., grinded from), skutterudite-based bulk materials, elemental materials, other non-Skutterudite-based materials, or combinations of such materials.
Ren, Zhifeng↗
Advanced thermoelectric materials with enhanced crystal lattice structure and methods of preparation
New skutterudite phases including Ru.sub.0.5 Pd.sub.0.5 Sb.sub.3, RuSb.sub.2 Te, and FeSb.sub.2 Te, have been prepared having desirable thermoelectric properties. In addition, a novel thermoelectric device has been prepared using skutterudite phase Fe.sub.0.5 Ni.sub.0.5 Sb.sub.3. The skutterudite-type crystal lattice structure of these semiconductor compounds and their enhanced thermoelectric properties results in semiconductor materials which may be used in the fabrication of thermoelectric elements to substantially improve the efficiency of the resulting thermoelectric device. Semiconductor materials having the desired skutterudite-type crystal lattice structure may be prepared in accordance with the present invention by using powder metallurgy techniques. Measurements of electrical and thermal transport properties of selected semiconductor materials prepared in accordance with the present invention, demonstrated high Hall mobilities and good Seebeck coefficients. These materials have low thermal conductivity and relatively low electrical resistivity, and are good candidates for low temperature thermoelectric applications.
Fleurial, Jean-Pierre↗
Thermoelectric properties of Co(x)Ni(4-x)Sb(12-y)Sn(y) ternary skutterudites
Thermoelectric materials based on the skutterudite crystal structure have demonstrated enhanced performance (ZT greater than 1), along with good thermal stability and favorable mechanical properties. Binary skutterudites, with single and multiple fillers, have been intensively studied in recent years. Compared to binary skutterudites, the ternary systems have received less attention, e.g. Ni4Sb8Sn4. Ternary skutterudites are isoelectronic variants of binary skutterudites; cation substitutions appear to be isostructural to their binary analogues. In general, ternary skutterudites exhibit lower thermal conductivity. Ternary systems of Ni4Bi8Ge4, Ni4Sb8Ge4, and Ni4Sb8Sn4 were investigated using combined solidification and sintering steps. Skutterudite formation was not achieved in the Ni4Bi8Ge4 and Ni4Sb8Ge4 systems; skutterudite formation occurred in Ni4Sb8Sn4 system. P-type material was achieved by Co substitution for Ni. Thermoelectric properties were measured from 298 K to 673 K for Ni4Sb8Sn4, Ni4 Sb7Sn5 and Co2Ni2Sb7Sn5. N-type Ni4Sb8Sn4 exhibit the highest figure of merit of 0.1 at 523 K.
Seebeck Effect↗
Low Thermal Conductivity Skutterudites
Recent experimental results on semiconductors with the skutterudite crystal structure show that these materials possess attractive trasport properties and have a good potential for achieving ZT values substantially larger than for state-of-the-art thermoelectic materials.
Thermal↗
Promising Thermoelectric Materials for Terrestrial-Space Applications
Since the discovery of state-of-the-art thermoelectric materials in the 1960s, little improvement has been made in the thermoelectric material efficiency. Although numerous materials have been investigated for their thermoelectric properties, ZT value of 1 has not been significantly exceeded. This paper presents a new family of materials with the skutterudite crystal structure which, based on initial results obtained on several compounds of this family, has a good potential for thermoelectric applications. This class of materials covers a wide range of decomposition temperatures and bandgaps, which could be used for low, intermediate to high temperature applications.
thermoelectric material skutterudite↗