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

2015 ◽  
Vol 29 (26) ◽  
pp. 1550154 ◽  
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.

High-Temperature Thermoelectric Properties of Pb- and La-Substituted Bi2Sr2Co2Oy Misfit Compounds

2010 ◽  
Vol 105-106 ◽  
pp. 336-338 ◽  
Author(s):  
Hao Shan Hao ◽  
Jin Qin Ye ◽  
Yong Tao Liu ◽  
Xing Hu
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Thermoelectric Performance ◽  
Simultaneous Increase ◽  
Reaction Method ◽  
Seebeck Coefficients

Pb- and La-substituted (Bi,Pb)2(Sr,La)2Co2Oy samples were prepared by solid-state reaction method and the effect of element substitution on the high-temperature thermoelectric properties was investigated. It was found that the presence of Pb and La elements improved the thermoelectric properties of the Bi2Sr2Co2Oy system owing to the simultaneous increase of conductivity and Seebeck coefficients. The optimal thermoelectric performance was obtained in Pb and La co-substituted samples and the power factor could reach 2.1×10-4Wm-1K-2 at 1000K.

Preparation and Thermoelectric Properties of Ca3Co4O9 Ceramics with Parallel Sheet Shaped Pores

2013 ◽  
Vol 544 ◽  
pp. 355-359
Author(s):  
Hua Dong Wang ◽  
Xu Dong Sun ◽  
Xue Yong Ding ◽  
Mu Zhang ◽  
Xiao Dong Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Solid State ◽  
Thermoelectric Properties ◽  
Solid State Reaction ◽  
Hollow Spheres ◽  
Solid State Reaction Method ◽  
High Ratio ◽  
Green Body ◽  
Reaction Method

Ca3Co4O9 powders were synthesized by a solid-state reaction method. Porous Ca3Co4O9 ceramics with parallel sheet shaped pores were prepared by a template sacrifice method using epispastic polystyrend (EPS) hollow spheres as the templates. During compaction of the green body, the EPS hollow spheres change into EPS discs due to the pressing force. After sintering, the pores in the Ca3Co4O9 ceramics are sheet shaped, well distributed and parallel to the pressing surface of compaction. The value of ZT merit of the porous Ca3Co4O9 sample obtained with 10 wt% EPS spheres is 0.0489. It was found that the ZT merit value can be improved by changing the density of sample to achieve a high ratio of electrical conductivity to thermal conductivity.

High-Temperature Thermoelectric Properties of Cu-Substituted Bi2Sr2Co2OY Oxides

2011 ◽  
Vol 228-229 ◽  
pp. 656-660
Author(s):  
Li Min Zhao ◽  
Wei Fen Jiang ◽  
Hao Shan Hao
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Solid State ◽  
Thermoelectric Properties ◽  
Solid State Reaction Method ◽  
Simultaneous Increase ◽  
Reaction Method ◽  
Seebeck Coefficients ◽  
Cu Substitution ◽  
Free Sample

Bi2Sr2Co2-xCuxOy (x=0.0, 0.2, 0.4) samples were prepared by solid-state reaction method and the effect of Cu substitution on the high-temperature thermoelectric properties was investigated. The presence of Cu element improved the grain size and the thermoelectric properties increased owing to the simultaneous increase of conductivity and Seebeck coefficients. The optimal thermoelectric performance was obtained in x=0.2 sample and the power factor was two times as large as that in Cu-free sample at 923K.

Effect of Ca and/or Mn substitution on thermoelectric properties of SrTiO3

2021 ◽  
Author(s):  
D. Mohan Radheep
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Mixed Valence ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Cubic Lattice ◽  
Mn Substitution

Thermoelectric properties have been investigated for Sr0.5Ca0.5Ti1-xMnxO3 (x = 0.25, 0.5, 0.75) and Sr0.75Ca0.25Ti0.75Mn0.25O3 perovskite polycrystalline samples synthesized by solid-state reaction method. Following physical properties such as thermal conductivity, electrical resistivity, Seebeck coefficient, power factor and figure of merit (ZT) were measured. The substitution of Ca2+ in Sr2+ site or/and mixed valence Mn in Ti site creates appreciable enhancement in the thermoelectric properties with an increase of ZT from 0.5 to 0.69 at room temperature. The origin for the enrichment of ZT of the investigated samples around room temperature is due to substitution induced distortion in the cubic lattice.

Thermoelectric properties of hole-doped Yb1-xPbxBaCo4O7+δ ceramics

2015 ◽  
Vol 29 (14) ◽  
pp. 1550082 ◽  
Author(s):  
Yubo Chen ◽  
Runxiang Ma ◽  
Kunlun Wang ◽  
Feng Gao ◽  
Xing Hu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Solid State ◽  
Figure Of Merit ◽  
Solid State Reaction Method ◽  
Doping Content ◽  
Reaction Method ◽  
Dimensionless Figure Of Merit ◽  
Ceramic Samples ◽  
Pb Doping

The effects of Pb doping on the thermoelectric (TE) properties of Yb 1-x Pb x BaCo4O7+δ (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.1) ceramic samples prepared by the solid-state reaction method were investigated from 383 K to 973 K. The results showed that with increase of the Pb content, the electrical resistivity decreased remarkably, meanwhile the Seebeck coefficient decreased slightly, resulting in an enhancement of the power factor (PF). The effect of Pb doping on the thermal conductivity was insignificant. According to the PF and the dimensionless figure of merit (ZT) value, the optimum Pb doping content was x = 0.08. The ZT value reached 0.12 at 973 K, being 69.5% higher than that of the sample without Pb doping.

Thermoelectric Properties of Cu-Substituted Bi2Ca2Co2Oy Misfit Oxides

2011 ◽  
Vol 284-286 ◽  
pp. 2263-2267 ◽  
Author(s):  
Hao Shan Hao ◽  
Qing Lin He ◽  
Li Min Zhao
Keyword(s):  
Electrical Conductivity ◽  
Grain Size ◽  
High Temperature ◽  
Solid State ◽  
Thermoelectric Properties ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Seebeck Coefficients ◽  
Cu Substitution ◽  
Performance System

Co2-xCuxOy (x=0.0, 0.2, 0.4) Samples were prepared by solid-state reaction method and the effect of Cu substitution on the thermoelectric properties was investigated. The presence of Cu element improved the grain size and electrical conductivity, but Seebeck coefficients were reduced by Cu substitution. It was found Cu substitution is an effective way to improve the thermoelectric performance system at high temperature.

Study of thermoelectric properties of Ca-doped LaCoO3

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540026 ◽  
Author(s):  
Kei-Ichiro Murai ◽  
Ken Nagai ◽  
Masaru Takahashi ◽  
Shosuke Takakusa ◽  
Toshihiro Moriga
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Ca Substitution

The samples of La 1-x Ca x CoO 3 (x = 0, 0.05, 0.10, 0.15) were synthesized by solid state reaction method for studying thermoelectric properties. The properties of electrical conductivity and Seebeck coefficient were measured in the temperature ranging from room temperature to 573 K. The results of electrical conductivity was increasing Ca substitution. The highest value of electrical conductivity is 1574 S/cm. It is concluded that Ca 2+ doping in LaCoO 3 has the effect to inhibit Seebeck coefficient from decreasing.

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