Structure and Electrical Properties of Yttria Stabilized Zirconia by Iron Ion Implantation

1993 ◽  
Vol 316 ◽  
Author(s):  
Wang Guomei ◽  
Qu Zuyuan

ABSTRACTFe ions were implanted into yttria stabilized zirconia with doses of 5×1015 -2×1017 ions/cm2 at an energy of 140 KeV. The effects of Fe-implanted zirconia and post-implantation thermal annealing on electrical properties and structure of an implanted layer were studies by electric measurement, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). It was found that the resistivity for the as-implanted sample decreased greatly with increasing ion dose, and at high dose the resistivity decreasing gradually. After annealing at 1200°C in N2 environment, the resistivity relative to that for the as-implanted sample had clearly marked decreases. Results of the XRD and XPS measurements showed that the implanted Fe ion was mainly in a charge state of Fe2+ and the sections of Fe2+ were incorporated into the ZrO2 lattice, forming a FeZrO3 compound. Finally, the conductivity mechanisms were discussed briefly.

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim

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.


2021 ◽  
Vol 21 (11) ◽  
pp. 5592-5602
Author(s):  
Samira Almasi ◽  
Ali Mohammad Rashidi

The effect of the yttria-stabilized zirconia (YSZ) nanoparticle loading in an electro-less bath was considered as one of the vital synthesis variables for control Ni content and microstructure of prepared nanocomposite particles, which are two crucial factors to achieving high-performance SOFC anode. Nanocomposite particles were prepared using a simple electroless method without any expensive pretreatment of sensitizing by Sn2+ ions as well as activating by Pd2+ ions that are usually used to apply nickel coating on the surface of a non-conductive substrate. The process was performed by adding YSZ nanoparticles into NaOH solution, separating them from the solution by the centrifugal method, then providing several water-based nanofluids with different concentrations of activated YSZ nanoparticles, mixing them with NiCI2 solution, followed by adding the hydrazine and then NaOH solution. X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray analysis were used to analyze the prepared nanocomposite particles. It is observed that after adding YSZ nanoparticles into the NaOH solution, the pH of the solution varied gradually from a starting pH of 10.2 to 9. Also, by increasing the YSZ nanoparticles loading in the electroless bath from 76 mg/l to 126 mg/l, the grain size of Ni deposits, the Ni content and the average size of the prepared nanocomposite particles decreased. The electrochemical mechanism previously proposed for the nickel ion reduction was modified, and a novel analytical model was proposed for variation of the efficiency of Ni deposition with YSZ nanoparticles loading.


1991 ◽  
Vol 05 (27) ◽  
pp. 1829-1835 ◽  
Author(s):  
Q.X. SU ◽  
L. LI ◽  
Y.Y. ZHAO ◽  
Y.Z. ZHANG ◽  
P. XU

Yttria-stabilized Zirconia(YSZ) films were deposited on (100)Si substrates by R.F. magnetron sputtering method. X-ray diffraction analysis showed that the best YSZ films were cubic in structure and was grown epitaxially with (100) orientation. The (200) peak of YSZ films was 0.8° of the full width at half of the maximum, X-ray diffraction based on Seemann-Bohlin focusing geometry showed no peaks. The morphology of the YSZ films was observed by scanning electron microscopy. The effects of the processing conditions (such as substrate temperature, oxygen partial pressure, etc.) on the structure of the film were also discussed.


2014 ◽  
Vol 32 (4) ◽  
pp. 702-708 ◽  
Author(s):  
M. Behera ◽  
G. Giri

AbstractHerein, we report a facile green synthesis of Cu2O nanoparticles (NPs) using copper sulfate as precursor salt and hydrazine hydrate as reducing agent in presence of bio-surfactant (i.e. leaves extract of arka — a perennial shrub) at 60 to 70 °C in an aqueous medium. A broad band centered at 460 nm in absorption spectrum reveals the formation of surfactant stabilized Cu2O NPs. X-ray diffraction pattern of the surfactant stabilized NPs suggests the formation of only Cu2O phase in assistance of a bio-surfactant with the crystallite size of ∼8 nm. A negative zeta potential of −12 mV at 8.0 pH in surfactant stabilized Cu2O NPs hints non-bonding electron transfer from O-atom of saponin to the surface of NP. Red-shift in the vibrational band (Cu-O stretching) of Cu2O from 637 cm−1 to 640 cm−1 in presence of bio-surfactant suggests an interfacial interaction between NPs and O-atoms of -OH groups of saponin present in the plant (i.e. Calotropis gigantean) extract. From X-ray photoelectron spectroscopy spectra, a decrease in binding energy of both 2p3/2 and 2p1/2 bands in Cu2O with saponin molecules as compared to bulk Cu atom reveals a charge transfer interaction between NP and saponin surfactant molecules. Transmission electron microscopy images show crystalline nature of Cu2O NPs with an fcc lattice.


1991 ◽  
Vol 235 ◽  
Author(s):  
Z. Tan ◽  
F. Namavar ◽  
S. M. Heald ◽  
J. I. Budnick ◽  
F. H. Sanchez

ABSTRACTWe have studied the silicide formation in Fe-implanted Si(100), with 1×1017-1×1018 Fe/cm2, using extended x-ray-absorption fine structure (EXAFS), x-ray diffraction and Rutherford backscattering spectrometry (RBS) methods. In the samples as-implanted at 350 °C, no silicide was observed at doses below 3×1017 Fe/cm2. At 5×1017 Fe/cm2, both α-FeSi2 and (β-FeSi2 form but α-FeSi2 appears to be the majority phase. As the dose increases to 7×1017 and above, ordered FeSi forms, but implantation damage is severe and a large number of Fe atoms are in very disordered environments. In addition to FeSi, Fe5Si3 was also observed in the 1×1018 Fe/cm2 sample. Upon post-implantation annealing at 700 °C or 900 °C, single phase P-FeSi2 was obtained independent of the dosage.


1999 ◽  
Vol 55 (5) ◽  
pp. 726-735 ◽  
Author(s):  
N. Ishizawa ◽  
Y. Matsushima ◽  
M. Hayashi ◽  
M. Ueki

The fluorite-related cubic structure of yttria-stabilized zirconia, Zr0.75 8Y0.24 2O1.87 9, has been studied by single-crystal X-ray diffraction using synchrotron radiation and by EXAFS. Two diffraction data sets obtained at X-ray energies of 512 and 10 eV below the Y K edge revealed that in the average structure Zr atoms are displaced from the origin of the space group Fm3¯m along 〈111〉 by 0.19 Å, while Y atoms reside at the origin. Approximately 48% of the O atoms occupy the ideal position in the fluorite-type structure, while 43% of O atoms are displaced from the ideal position along 〈001〉 by 0.31 Å. The remaining 9% of O atoms are presumably sited at interstitial positions. Local structures around Zr and Y are investigated by combining the results of single-crystal X-ray diffraction and EXAFS studies.


2007 ◽  
Vol 124-126 ◽  
pp. 235-238
Author(s):  
Moon Jin Hwang ◽  
Chong Soo Han

Porous YSZ(8 mol% yttria-stabilized zirconia) was prepared by an acid leaching of ZnO-YSZ composite. The ZnO-YSZ composites were obtained by two different methods, a 1450 °C sintering of the mechanical mixture of ZnO and YSZ powders or a decomposition of Zn(NO3)2 deposited on YSZ and a subsequent sintering. The XRD (X-ray diffraction) pattern of the composite indicated that it was a mixture of ZnO and YSZ even after the sintering. Sharp edge or round edge of YSZ was observed in SEM (Scanning Electron Microscope) image of the porous-YSZ from the mixture of ZnO and YSZ, or Zn(NO3)2 deposited on YSZ, respectively. The porous YSZ from the composite having ZnO component greater than 60 wt% shows low mechanical strength. As the ZnO content of the composite increased, the porosity and gas permeability of the porous YSZ increased. From the result, it was suggested that ZnO is a candidate to generate pores in YSZ bulk or membrane.


Author(s):  
G. Benay ◽  
G. Modolo ◽  
R. Odoj

In the scope of the co-conversion of actinides solutions obtained from partitioning spent nuclear fuel, the internal gelation of ceria-doped yttria-stabilized zirconia was investigated. This dust-free method to fabricate kernels, which can be used as fuel or pressed into pellets, is technically easy to implement and compatible with remote handling. The effects of the quantity of reactants used on the properties of the material were studied. Gels, kernels and pellets were analyzed by thermal analysis, electron microscopy and X-ray diffraction. It was found that the initial broth composition played an important role in the structure of kernels and the formation of cracks during thermal treatment. Pellets obtained with a repressing method were found to present densities up to 86% TD.


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