Fabrication and thermoelectric properties of Ca3Co4O9/Ag composites

Enhancement of mechanical and thermoelectric properties of Ca3Co4O9 by Ag addition

“…7. [46], but lower than the measured in 10 wt.% Ag added samples prepared by a more complex method followed by hot pressing (about 1 mW/K 2 .m) [35]. In spite of these results, all the obtained data in this work clearly show that Ag additions in Ca 3 Co 4 O 9 ceramics can be used to produce high performance TE materials with randomly oriented grains by a simple, rapid, and economic route.…”

“…The lowest value at 800 ºC (~ 10 m.cm for the 10 wt.% Ag samples) is still higher than the values measured in hot pressed samples with 0, 5, and 10 vol.% Ag at the same temperature (about 9, 5, and 2 m.cm, respectively) and measured perpendicular to the pressing direction [46]. [35,46].…”

“…The lowest measured room temperature resistivity values (~ 12 m.cm for the 10 wt.% Ag samples) is much lower than the obtained in the pure Ca 3 Co 4 O 9 samples (about samples produced by a more complex method followed by hot pressing (around 6, 5, and 3 m.cm for the 0, 5, and 10 wt% Ag, respectively) and measured perpendicular to the pressing direction [35]. The lowest value at 800 ºC (~ 10 m.cm for the 10 wt.% Ag samples) is still higher than the values measured in hot pressed samples with 0, 5, and 10 vol.% Ag at the same temperature (about 9, 5, and 2 m.cm, respectively) and measured perpendicular to the pressing direction [46]. [35,46].…”

Thermopower of an Oxide-Alloy Composite System Obtained by In Situ Carbothermal Synthesis

“…It has been reported that the power factor (PF) of cobaltite thermoelectric oxide materials was effectively increased by adding metallic silver particles. 5,6 For these TE alloy materials, such as FeSi 2 , ZrNiSn, and also CoSb 3 , reduction of thermal conductivity by the introduction of oxide particles into the alloy matrix has been verified. 7 From the viewpoint of lowering the electrical resistivity and thermal conductivity more effectively, composite material composed of TE alloy and oxide is a good choice.…”

“…5 In this work, in situ carbothermal synthesis was used to prepare oxide-alloy composites. In situ carbothermal synthesis is a reduction reaction between metal oxides and solid carbon that occurs in situ at high temperature, usually being employed to reduce oxide to metal in metallurgy.…”