Sintering of yttria-stabilized zirconia nanopowders studied by positron annihilation spectroscopy

The effect of chromia additive on defects in yttria stabilized zirconia (YSZ) nanopowders was investigated in this work. It was found that positrons are trapped at vacancy-like misfit defect at grain boundaries and at larger defects situated at triple points. Moreover, a long-lived ortho-positronium contribution was found in YSZ nanopowder without chromia. Addition of chromia prolongs the lifetime of positrons trapped at vacancy-like misfit defects which indicates segregation of Cr ions at grain interfaces and interaction of Cr with vacancy-like misfit defets. Moreover addition of chromia completely suppresses formation of positronium.

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Preparation of alumina-doped yttria-stabilized zirconia nanopowders by microwave-assisted peroxyl-complex coprecipitation

Transactions of Nonferrous Metals Society of China ◽

10.1016/s1003-6326(06)60226-4 ◽

2006 ◽

Vol 16 ◽

pp. s426-s430 ◽

Cited By ~ 6

Author(s):

Liang QI ◽

Ming-xia XU ◽

Yu-ming TIAN ◽

Jin-wei ZHAO

Keyword(s):

Yttria Stabilized Zirconia ◽

Stabilized Zirconia ◽

Microwave Assisted ◽

Zirconia Nanopowders

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Microstructural examination of modified yttria stabilized zirconia by EM analytical techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100145558 ◽

1986 ◽

Vol 44 ◽

pp. 842-843

Author(s):

W. W. Davison ◽

R. C. Buchanan

Keyword(s):

Mechanical Properties ◽

Analytical Techniques ◽

Yttria Stabilized Zirconia ◽

Stabilized Zirconia ◽

Transmission Microscopy ◽

Sintering Aid ◽

Densification Temperature ◽

Chemical Inertness ◽

Scanning Transmission ◽

Microstructural Examination

Yttria stabilized zirconia (YSZ) has become a significant technological material due to its high ionic conductivity, chemical inertness, and good mechanical properties. Temperatures on the order of 1700°C are required, however, to densify YSZ to the degree necessary for good electrical and mechanical properties. A technique for lowering the densification temperature is the addition of small amounts of material which facilitate the formation of a liquid phase at comparatively low temperatures. In this study, sintered microstructures obtained from the use of Al2O3 as a sintering aid were examined with scanning, transmission, and scanning transmission microscopy (SEM, TEM, and STEM).

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Positron annihilation spectroscopy

Physics Subject Headings (PhySH) ◽

10.29172/fd184070f49e405c9e6642f7ee162475 ◽

2018 ◽

Keyword(s):

Positron Annihilation ◽

Positron Annihilation Spectroscopy

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Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

Engineering and Technology Journal ◽

10.30684/etj.v38i4a.351 ◽

2020 ◽

Vol 38 (4A) ◽

pp. 491-500

Author(s):

Abeer F. Al-Attar ◽

Saad B. H. Farid ◽

Fadhil A. Hashim

Keyword(s):

Ionic Conductivity ◽

Electrochemical Impedance ◽

Structural Information ◽

Impedance Analysis ◽

High Energy ◽

Yttria Stabilized Zirconia ◽

X Ray Diffraction ◽

Stabilized Zirconia ◽

Powder Morphology ◽

X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

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