Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 5

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  88.30.pn
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Characterization of Nd and Sm Co-Doped CeO₂-Based Systems

100%
Arabacı A., Der M., Öksüzömer M., Altınçekiç T.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 1
78-81
EN
Nd_{0.20}Sm_{x}Ce_{0.8-x}O_{1.9-x/2} (x=0, 0.05, 0.10, 0.15, 0.20) rare-earth-co-doped ceria electrolytes were synthesized by polyol process. Acetate compounds of cerium and dopants (Nd, Sm) were used as starting materials and triethylene glycol was used as a solvent. Structural and ionic conductivity properties of the electrolyte systems were determined by applying characterization techniques such as X-ray diffraction, the Fourier transform infrared spectroscopy, scanning electron microscope, and electrochemical impedance spectroscopy. The results of X-ray diffraction indicated that a single-phase fluorite structure formed at the relatively low calcination temperature of 600°C. So, the samples were calcined at 600°C for 4 h and then sintered at 1400°C for 6 h to obtain dense ceramics (between 85 and 90%). The two-probe ac impedance spectroscopy was used to study the total ionic conductivity of doped and co-doped ceria samples. The results of the impedance spectroscopy indicate that the Nd_{0.20}Sm_{0.05}Ce_{0.75}O_{1.875} composition exhibited highest ionic conductivity value, 3.60×10¯² S cm¯¹ at 800°C.
2
Content available remote

Characteristics of Samaria-Doped Ceria Prepared by Pechini Method

100%
Arabacı A., Serin Ö.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 2B
B-118-B-121
EN
CeO₂ ceramics doped with 20 mol.% samarium (SDC-20) were prepared through the Pechini process. The samples were calcined at 400, 700 and 1000°C. The sintering behavior of the calcined SDC-20 powders was also investigated at 1400°C for 6 h. Microstructural and physical properties of SDC-20 samples were characterized with X-ray diffraction, scanning electron microscopy, thermogravimetry and impedance analysis methods. The results of the thermogravimetry/differential thermal analysis and X-ray diffraction indicated that a single-phase fluorite structure formed at a relatively low calcination temperature of 400°C. It is understood from the measured ionic conductivity values that the pellet formed from the SDC-20 samples calcined at 1000°C had lower resistance of grain-boundary than those of the pellets formed from the SDC-20 samples calcined at 400 and 700°C. The maximum ionic conductivity was measured as 1.95× 10⁻² S cm⁻¹ at 800°C for the sintered SDC-20 pellet obtained from SDC-20 powders calcined at 1000°C.
3
Content available remote

Characterization of Sm and Nd Co-Doped Ceria-Based Electrolyte Materials

100%
Arabacı A., Serin Ö., Sarıboğa V., Öksüzömer M.
Acta Physica Polonica A
|
2016
|
vol. 129
|
issue 4
524-527
EN
Ceria doped with trivalent cations, such as rare earth elements, is considered to be one of the most promising electrolyte materials for intermediate-temperature solid oxide fuel cells, which are an alternative to the commercially used ytrium-stabilized zirconia (YSZ). The aim of this work research is to synthesize Sm and Nd co-doped ceria materials using the Pechini method as solid electrolyte for intermediate temperature solid oxide fuel cell. Ce_{0.75}Sm_{0.20}Nd_{0.05}O_{1.875}, Ce_{0.65}Sm_{0.20}Nd_{0.15}O_{1.825}, and Ce_{0.60}Sm_{0.20}Nd_{0.20}O_{1.80} have been chosen as target of this study. Microstructural and physical properties of the samples were characterized with X-ray diffraction, scanning electron microscopy, thermogravimetric analysis methods. The results of the thermogravimetry/differential thermal analysis and X-ray diffraction indicated that a single-phase fluorite structure formed at the relatively low calcination temperature of 600°C for 3 h. The two-probe ac impedance spectroscopy was used to study the total ionic conductivity of doped and co-doped ceria ceramics at 800°C. The Ce_{0.60}Sm_{0.20}Nd_{0.20}O_{1.80} sample showed maximum ionic conductivity.
4
Content available remote

Structural Analysis of Ce Doped La_{1-x}Sr_xCo_{1-y}Fe_yO_{3-δ} Nanopowders Synthesized by Glycine-Nitrate Gel Combustion

51%
Yildiz Ö., Soydan A., Ata A., İpçızade E., Akin D., Uçak Ö.
|
|
vol. 125
|
issue 2
669-672
EN
Ce doped La_{1-x}Sr_xCo_{1-y}Fe_yO_3 (LCSCF) is a widely used cathode material due to its high catalytic activity for oxygen reduction and high oxygen exchange coefficient. LCSCF is also known with its high ionic and electronic conductivities and low electrode polarization losses which are highly critical properties for low temperature solid oxide fuel cell applications. In this study, structural properties of the LCSCF cathode nanopowder materials synthesized by glycine-nitrate gel combustion have been investigated by X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and nanosizer. Synthesized nanopowders represent volcanic ash like structures and morphologies. Ce, Sr, Co, and Fe are found to have significant effects on the structural properties of powders in terms of powders morphology, agglomerate structure, crystallite size and also lattice parameter of perovskite crystal. All synthesized ash powders have particle sizes around 50-600 nm, varying crystalline structures of perovskite and fluorite depending on molar ratio of Ce in the composition. Increasing molar Ce ratio over 0.4 is found to lead to the formation of a separate nano ceria phase in fluorite crystal structure on the surface of the synthesized powder.
5
Content available remote

Corrosion Behavior of Crofer 22APU for Metallic Interconnects in Single and Dual Atmosphere Exposures at 1073 K

44%
Stygar M., Matsuda K., Lee S., Brylewski T.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 5
1394-1398
EN
To determine the impact of an oxidizing Ar-H₂-H₂O/air dual atmosphere on the kinetics and mechanism of oxidation of the Crofer 22APU steel as compared to oxidation in a single atmosphere (Ar-H₂-H₂O or air), the oxidation kinetics of this steel were investigated both in single and dual reaction atmospheres at 1073 K during 100, 250, 500, and 1000 h of oxidation. Detailed morphological observations and the results of chemical composition analyses carried out using transmission electron microscopy combined with energy-dispersive X-ray spectroscopy revealed the presence of Fe in the scale formed on the cathode side in the dual atmosphere. Based on morphological observations (scanning- and transmission electron microscopies) and chemical and phase composition analyses (energy-dispersive X-ray spectroscopy and X-ray diffraction, respectively) of the products of oxidation of the Crofer 22APU steel, and on the determined oxidation kinetics, a mechanism describing scale growth on both sides of the steel during its oxidation in conditions involving a gradient of the chemical potential of oxygen and hydrogen was proposed.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.