Nidhi Puri; Raj K. Gupta; Akhyaya K. Pattanaik; Navin C. Mehra; Ajit K. Mahapatro; Ram P. Tandon
Abstract
The present paper highlights the synthesis of cobalt antimonide (CoSb3) micro/nanostructures by following solvothermal technique with water as solvent. Recipe is optimized for preparation of refined CoSb3 compounds and demonstrated that a high processing temperature of 500 °C and long duration of ...
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The present paper highlights the synthesis of cobalt antimonide (CoSb3) micro/nanostructures by following solvothermal technique with water as solvent. Recipe is optimized for preparation of refined CoSb3 compounds and demonstrated that a high processing temperature of 500 °C and long duration of 72 hr indicates presence of CoSb3 phase. The microstructures and composition of the as synthesized CoSb3 nanocomposites are characterized to achieve the optimized phase.The morphologies as imaged using field emission scanning electron microscope resemble granules for the as-synthesized CoSb3. The phase purity and crystallographic structure of the as-synthesized CoSb3 nanocomposites as determined by XRD indicates the formation of the cubic phase of CoSb3 and agrees well with the JCPDS data mentioned for the highly pure CoSb3. The EDX estimates the elemental composition of Co and Sb in 1:3 stoichiometric ratio for the as-synthesized CoSb3. The currently prepared nanosized skutterudite CoSb3 material synthesized by solvothermal method could be utilized as active material for the development of highly efficient thermoelectric devices. Copyright © 2018 VBRI Press.
Raj K. Gupta; Ajit K. Mahapatro; Ram P. Tandon
Abstract
This work demonstrates the achievement of high thermopower in the pellets of calcium cobalt oxide (Ca3Co4O9) co-doped with aluminium (Al) and titanium (Ti). The pellets of Ca(3-x)AlxCo(4-y)TiyO9+δ with x, y = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5, oxide ceramics are prepared using a hot-press machine ...
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This work demonstrates the achievement of high thermopower in the pellets of calcium cobalt oxide (Ca3Co4O9) co-doped with aluminium (Al) and titanium (Ti). The pellets of Ca(3-x)AlxCo(4-y)TiyO9+δ with x, y = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5, oxide ceramics are prepared using a hot-press machine by applying an uniaxial pressure of 70 MPa at a dwell temperature of850 ºC. Microstructure imaging reveals compactness of good connectivity among grains with the estimated density using Archimedes principle suggests the formation of near perfect (99%) relative density for the new pelleted ceramics. All theco-doped samples exhibit lower electrical resistivity (r) values compared to pure Ca3Co4O9. The maximum Seebeck coefficient (S) of 177 μV/K at 750 K is achieved for the pure Ca3Co4O9 sample. A significant improvement of 18% in the power factor (S2/r) is realized at 750 K in the co-doped samples containing 0.2 mol% of Al and Ti co-doping. The demonstration of significant thermoelectric properties of Ca(3-x)AlxCo(4-y)TiyO9+δ suggest that these materials could be utilized as promising active material in thermoelectrics. Copyright © 2018 VBRI Press.
