Synthesis and thermoelectric properties of Ce(Ru0.67Rh0.33)4Sb12.

ABSTRACTExotic filled skutterudite compositions show promise for thermoelectric applications. Current work was undertaken with a nominal composition of Ce(Ru0.67Rh0.33)4Sb12 to experimentally verify its potential as an n-type thermoelectric material. Nominal electroneutrality was expected at 0.89 cerium filling and fully filled materials were expected to be strongly n-type. Filled precursors of the nominal composition were synthesized using straightforward solid state reaction techniques, but standard synthesis routes failed to produce a fully-filled homogenous phase. Instead, the filled thermoelectric Ce(Ru0.67Rh0.33)4Sb12 was synthesized using a combination of solid state reaction of elemental constituents and high pressure hot pressing. A range of pressure-temperature conditions was explored; the upper temperature limit of filled skutterudite in this system decreases with increasing pressure and disappears by 12 GPa. The optimal synthesis was performed in multi-anvil devices at 4–6 GPa pressure and dwell temperatures of 350–700 °C. rutheniumThe result of this work, a Ce(Ru0.67Rh0.33)4Sb12 fully filled skutterudite material, exhibited unexpected p-type conductivity and an electrical resistance of 1.755 mΩ-cm that increased with temperature. Thermal conductivity, Seebeck coefficient, and resistivity were measured on single phase samples. In this paper, we report the details of the synthesis routeand measured thermoelectric properties, speculate on the deviation from expected carrier charge balance, and discuss implications for other filled skutterudite systems.

Download Full-text

Thermoelectric Properties of High Density Sintered Ca3Co2O6

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.54.211 ◽

2008 ◽

Vol 54 ◽

pp. 211-215 ◽

Cited By ~ 2

Author(s):

Takeo Uesugi ◽

Hitoshi Kohri ◽

Ichiro Shiota ◽

Masahiko Kato ◽

Isao J. Ohsugi

Keyword(s):

Solid State ◽

Thermoelectric Properties ◽

Solid State Reaction ◽

Hot Pressing ◽

Temperature Limit ◽

Thermoelectric Oxide ◽

Temperature Range ◽

Seebeck Coefficients ◽

The One ◽

Lower Resistivity

Ca3Co4O9 is a promising material for thermoelectric generation, as it is stable up to 1173 K in the air, and shows good thermoelectric properties. Recently, it was found that Ca3Co2O6 was stable up to 1300 K in the air. The Ca3Co2O6 is decomposed phase of Ca3Co4O9 and the temperature limit is higher than one of Ca3Co4O9. The electrical resistivity of Ca3Co2O6 was, however, higher than the one of Ca3Co4O9. Not only high power generation performances but also excellent strength is required for practical use of the thermoelectric oxide materials. Polycrystalline samples of Ca3Co2O6 were prepared by solid-state reaction (SSR) and hot pressing (HP). Relative density of Ca3Co2O6 (HP) was over 98%, which is larger than the one of Ca3Co2O6 (SSR). Ca3Co2O6 (HP) showed larger strength and lower resistivity than Ca3Co2O6 (SSR). The resistivity (ρ) of Ca3Co2O6 (HP) in perpendicular to the pressurized direction decreased from 64 Ωcm to 4.0×10-2 Ωcm at the temperature range between 373 and 1173 K. In addition, the resistivity of this sample was decreased by heat treatment in the air. The Seebeck coefficients (S) of Ca3Co2O6 (HP) was positive value and more than 160 μVK-1 at the temperature range between 373 and 1173 K. Ca3Co1.8M0.2O6 (M= Mn or V) were prepared by solid state reaction and hot pressing. The resistivity of Mn-substituted Ca3Co2O6 (HP-Mn) and V-substituted Ca3Co2O6 (HP-V) were lower than the one of non-substituted Ca3Co2O6 (HP) at the temperature below 523 K for the Mn-substituted sample or 723 K for V-substituted sample. The latter showed the lowest value 1.53 Ωcm of all specimens at 383 K. The power factor (S2ρ-1) of Ca3Co2O6 (HP) was 88.3 μWm-1K-2, which is the largest of all specimens at 1176 K, but S2ρ-1 of V-substituted Ca3Co2O6 (HP-V) is the largest of all specimens up to 773 K.

Download Full-text

Thermoelectric properties of Cu3SbSe3 with intrinsically ultralow lattice thermal conductivity

Journal of Materials Chemistry A ◽

10.1039/c4ta02590c ◽

2014 ◽

Vol 2 (38) ◽

pp. 15829-15835 ◽

Cited By ~ 34

Author(s):

Kriti Tyagi ◽

Bhasker Gahtori ◽

Sivaiah Bathula ◽

A. K. Srivastava ◽

A. K. Shukla ◽

...

Keyword(s):

Thermal Conductivity ◽

Solid State ◽

Spark Plasma Sintering ◽

Thermoelectric Properties ◽

Solid State Reaction ◽

Electrical Transport ◽

Single Phase ◽

Lattice Thermal Conductivity ◽

Plasma Sintering ◽

Spark Plasma

Intrinsically ultra-low thermal conductivity and electrical transport in single-phase Cu2SbSe3 synthesized employing a solid state reaction and spark plasma sintering.

Download Full-text

Thermoelectric properties of Sb-doped tin oxide by a one-step solid-state reaction

Ceramics International ◽

10.1016/j.ceramint.2021.10.137 ◽

2021 ◽

Author(s):

Leilane R. Macario ◽

Andrew Golabek ◽

Holger Kleinke ◽

Edson R. Leite

Keyword(s):

Solid State ◽

Thermoelectric Properties ◽

Tin Oxide ◽

Solid State Reaction ◽

One Step

Download Full-text

Influence of R3+ ion sizes on the thermoelectric properties of RBaCo4O7+δ ceramics

Modern Physics Letters B ◽

10.1142/s0217984915501547 ◽

2015 ◽

Vol 29 (26) ◽

pp. 1550154 ◽

Cited By ~ 4

Author(s):

F. Gao ◽

Q. L. He ◽

F. Wu ◽

D. L. Yang ◽

X. Hu ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Solid State ◽

Thermoelectric Properties ◽

Solid State Reaction ◽

Solid State Reaction Method ◽

Oxygen Adsorption ◽

Reaction Method ◽

Transition Phenomenon ◽

Seebeck Coefficients

The influence of [Formula: see text] ion sizes on the electrical resistivity, Seebeck coefficients, thermal conductivity and [Formula: see text] values of [Formula: see text] prepared by the solid-state reaction method was investigated from 373 K to 973 K. The electrical resistivity decreases with decreasing [Formula: see text] ion sizes. Both the electrical resistivity and the Seebeck coefficients have a transition at about 630 K. Especially, the transition phenomenon disappears gradually with decreasing [Formula: see text] ion sizes, and is attributed to the oxygen adsorption of [Formula: see text]. The [Formula: see text] values increase with rising temperature or decreasing [Formula: see text] ion sizes. The [Formula: see text] with the smallest [Formula: see text] size has the maximum [Formula: see text] value that reaches 0.1 at 973 K.

Download Full-text

Microstructure Investigation of Non-equilibrium Synthesized Filled Skutterudite CeFe4Sb12

MRS Proceedings ◽

10.1557/proc-1267-dd05-25 ◽

2010 ◽

Vol 1267 ◽

Cited By ~ 2

Author(s):

Juan Zhou ◽

Qing Jie ◽

Qiang Li

Keyword(s):

Electron Microscopy ◽

Grain Size ◽

Grain Boundaries ◽

Thermoelectric Properties ◽

Conventional Solid State Reaction ◽

Filled Skutterudite ◽

Filled Skutterudites ◽

Higher Carrier Mobility ◽

P Type ◽

Non Equilibrium

AbstractWe have prepared a variety of filled skutterudites through non-equilibrium synthesis by converting melt-spun ribbons into single phase polycrystalline bulk under pressure. In general, better thermoelectric properties are found in these samples. In this work, we performed microstructure characterization of non-equilibrium synthesized p-type filled skutterudite CeFe4Sb12 by X-ray diffraction, scanning electron microscopy and transmission electron microscopy in order to understand the structural origin of the improved thermoelectric properties. It is found that the non-equilibrium synthesized samples have smaller grain size and cleaner grain boundaries when compared to the samples prepared by the conventional solid-state reaction plus long term annealing. While smaller grain size can help reduce the lattice thermal conductivity, cleaner grain boundaries ensure higher carrier mobility and subsequently, higher electrical conductivity at the application temperatures.

Download Full-text

Thermoelectric Properties Enhancement of NaCo2O4 through Ca Atom Partial Substitution on Na Atom

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1123.140 ◽

2015 ◽

Vol 1123 ◽

pp. 140-144 ◽

Cited By ~ 2

Author(s):

Erwin Ermawan ◽

Suhardjo Poertadji

Keyword(s):

Solid State ◽

Thermoelectric Properties ◽

Solid State Reaction ◽

Single Phase ◽

Substitution Effect ◽

Charge Carriers ◽

Reaction Process ◽

Partial Substitution ◽

Positive Sign ◽

Power Properties

Single phase samples of Na1-xCaxCo2O4 (with x = 0, 0.1, 0.2 and 0.3) are prepared by utilizing a solid state reaction process, and the Ca2+ substitution effect on thermoelectric properties is then observed. On the samples, the increment of Ca2+ substitution results in the increase of resistivity and thermo power properties. The Ca2+ substitution in NaCo2O4 reduces charge carriers of the samples. This phenomenon indicates that there are many holes in the samples and it is consistent with the positive sign of thermo power. It demonstrates that the Ca2+ substitution is effective to enhance thermoelectric properties.

Download Full-text