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.

Na-Site Doping of NaCo2O4 Thermoelectric Materials

2007 ◽  
Vol 336-338 ◽  
pp. 802-804 ◽  
Author(s):  
Ying Li ◽  
Li Hua Zhang ◽  
Shu Lan Wang ◽  
Gui Ying Xu ◽  
Mao Fa Jiang
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Maximum Power ◽  
Reaction Method

The K, Ca, Sr and Ce doped and non-doped γ-NaxCo2O4 samples were prepared by the solid-state reaction method. Results show that the Na-site doping might lead to an increase in the Seebeck coefficient and a decrease in the electrical conductivity of the samples. The maximum power factors of the K, Ca and Sr doped samples are respectively 2.04, 1.93 and 1.9 W·m-1·K-2, corresponding to an increase by 58%, 50% and 47% compared with that of the non-doped samples. Thus, the Na-site doping can improve the thermoelectric properties of γ-NaxCo2O4 oxides.

TEXTURED STRUCTURE AND ANISOTROPIC THERMOELECTRIC PROPERTIES OF Ca2.7Bi0.3Co4O9 OXIDE PREPARED BY CONVENTIONAL SOLID-STATE REACTION

2009 ◽  
Vol 23 (01) ◽  
pp. 87-95 ◽  
Author(s):  
HAOSHAN HAO ◽  
QINGLIN HE ◽  
CHANGQING CHEN ◽  
HONGWEI SUN ◽  
XING HU
Keyword(s):  
Electrical Conductivity ◽  
Grain Size ◽  
Solid State ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Bi Doping

Ca 3-x Bi x Co 4 O 9(x = 0.0, 0.3) samples have been prepared at 1223 K by conventional solid-state reaction method. XRD and SEM investigations reveal that c-axis-oriented structure could be formed in Ca 2.7 Bi 0.3 Co 4 O 9 samples, whereas grains in Ca 3 Co 4 O 9 samples distribute randomly. Moreover, Bi doping increases the grain size and relative density of Ca 2.7 Bi 0.3 Co 4 O 9. The electrical conductivity along the ab plane for Ca 2.7 Bi 0.3 Co 4 O 9 is about four times as large as that along the c-axis, but the Seebeck coefficient is almost isotropic, which leads to a remarkable rise of the power factor in ab plane for Ca 2.7 Bi 0.3 Co 4 O 9 compared with untextured Ca 3 Co 4 O 9. The textured structure in Ca 2.7 Bi 0.3 Co 4 O 9 sample should be attributed to the effect of Bi doping.

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.

Facile preparation of polyoxometalate nanoparticles via a solid-state chemical reaction for aerobic oxidative desulfurization catalysis

2021 ◽  
Author(s):  
Hang Yu ◽  
Wenwen Bu ◽  
Zijia Wang ◽  
Zhuoyue Zhao ◽  
Mehwish Jadoon ◽  
...  
Keyword(s):  
Solid State ◽  
Silver Nitrate ◽  
Chemical Reaction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Oxidative Desulfurization ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
State Chemical ◽  
Facile Preparation

Polyoxometalate nanoparticles were synthesized via a concise solid-state reaction method by directly grinding silver nitrate and the polyoxometalate (NH4)5H6PMo4V8O40 at room temperature without the assistance of a surfactant.

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.

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