14 documents found, page 1 of 2
Mechanosynthesis and electrical conductivity of undoped and calcium-substituted...
Fabián, Martin; Arias-Serrano, Blanca I.; Briančin, Jaroslav; Yaremchenko, AlekseyGadolinium aluminate (GdAlO3) and its calcium-substituted derivates (Gd1-xCaxAlO3-δ; x = 0.05, 0.10 and 0.15) are prepared via one-step mechanochemical processing of simple oxide precursors at ambient temperature. The mechanochemical reaction is accompanied by Gd2O3 phase transformation. The as-prepared and sintered materials are characterized by X-ray diffraction and scanning electron microscopy. Sintering at ...
Microstructural aspects affecting the performance of thermoelectric oxides: sel...
Kovalevsky, Andrei V.; Arias-Serrano, Blanca I.; Constantinescu, Gabriel; Zakharchuk, Kiryl; Rasekh, Shahed; Ferreira, Nuno M.; Xie, WenjieOxide materials represent certain advantages as compared to traditional thermoelectric materials, including stability at high temperatures and versatility regarding the gas atmosphere composition. Microstructural aspects play a crucial role in the performance of oxides, often dominating even over chemical composition effects. Thus, engineering the microstructure in these materials represents a powerful tool tow...
Specific microstructural effects on the performance of thermoelectric oxides
Kovalevsky, Andrei V.; Arias-Serrano, Blanca I.; Mikhalev, Sergey M.; Constantinescu, Gabriel; Zakharchuk, Kiryl V.; Sergiienko, Sergii A.Oxide materials possess notable high-temperature and chemical stability, thus representing certain advantages over traditional thermoelectrics. The thermoelectric performance of oxides is strongly affected by the microstructure, often even dominating over the chemical composition effects. Thus, engineering the microstructure in these materials represents a powerful tool towards improving their thermoelectric pe...
On the high-temperature degradation mechanism of ZnO-based thermoelectrics
Arias-Serrano, Blanca I.; Mikhalev, Sergey M.; Ferro, Marta C.; Tobaldi, David M.; Frade, Jorge R.; Kovalevsky, Andrei V.The stability and reproducibility of the electric properties in n-type doped ZnO represent known bottlenecks towards potential thermoelectric applications. The degradation is promoted by the vanishing of the electronic defects on oxidation and irreversible exsolution of the phase impurities. This work proposes a microstructural mechanism showing that these processes take place mainly in the pores and highlighti...
Mixed ionic-electronic conductivity, redox behavior and thermochemical expansio...
Natoli, Alejandro; Arias-Serrano, Blanca I.; Rodríguez-Castellón, Enrique; Żurawska, Agnieszka; Frade, Jorge R.; Yaremchenko, Aleksey A.Manganese-substituted 5 mol.% yttria-stabilized zirconia (5YSZ) was explored as a prospective material for protective interlayers between electrolyte and oxygen electrodes in reversible solid oxide fuel/electrolysis cells. [(ZrO2)0.95(Y2O3)0.05]1-x[MnOy]x (x = 0.05, 0.10 and 0.15) ceramics with cubic fluorite structure were sintered in air at 1600 °C. The characterization included X-ray diffraction (XRD), scann...
Ionic-electronic transport in zircon-type PrVO4-based ceramics
Pinto, Rui G.; Arias-Serrano, Blanca I.; Yaremchenko, Aleksey A.No abstract available.
Strontium titanate and zinc-oxide-based materials for high-temperature thermoel...
Kovalevsky, Andrei V.; Zakharchuk, Kiryl V.; Ferreira, Nuno M.; Xie, Wenjie; Patrício, Sonia G.; Arias-Serrano, Blanca I.; Mikhalev, Sergey M.Broad societal needs have focused increased attention to providing a sustainable energy supply to the population, based on technologies with minimal environmental impact and reduced fossil fuels usage. One solution is to improve energy conversion efficiency in key consuming sectors. Since most of the energy (60-70%) used worldwide is discharged as waste heat, ”green” thermoelectric (TE) conversion has received ...
Electrical conductivity and thermal expansion of Ln-substituted SrTiO3 for soli...
Yaremchenko, Aleksey A.; Macías, Javier; Kovalevsky, Andrei V.; Arias-Serrano, Blanca I.; Frade, Jorge R.The present work aims to evaluate relevant effects of the size of substituting rare-earth cation on electrical conductivity and thermal expansion of donor-doped SrTiO3 as ceramic components of electrochemical solid electrolyte cells. A series of strontium titanate-based ceramics with a moderate doping level and different cation stoichiometry, Sr0.90Ln0.10TiO3±δ and Sr0.85Ln0.10TiO3±δ (Ln = La-Yb), are prepared ...
Ionic and electronic transport in calcium-substituted LaAlO3 perovskites prepar...
Fabián, Martin; Arias-Serrano, Blanca I.; Yaremchenko, Aleksey; Kolev, Hristo; Kaňuchová, Mária; Briančin, JaroslavThe present work explores mechanosynthesis of lanthanum aluminate-based perovskite ceramics and corresponding effects on ionic-electronic transport properties. La1-xCaxAlO3-δ (x = 0.05-0.20) nanopowders were prepared via one-step high-energy mechanochemical processing. Sintering at 1450°C yielded dense ceramics with submicron grains. As-prepared powders and sintered ceramics were characterized by XRPD, XPS and ...
PrOx-infiltrated LnNiO3-based oxygen electrodes for solid oxide cells
Yaremchenko, Aleksey; Arias-Serrano, Blanca I.; Zakharchuk, Kiryl; Frade, JorgeLn2NiO4+δ and its derivatives with perovskite-related K2NiF4-type structure demonstrate high mixed ionic-electronic conductivity, moderate thermal and negligible chemical expansion. As a result, these phases attracted significant attention as prospective cathode materials for intermediatetemperature solid oxide fuel cells (IT-SOFC). At the same time, perovskite-like LnNiO3 have not been considered for these app...