ESR centers in reduced stabilized zirconia

Ben-Michael, R.; Tannhauser, D. S.; Genossar, J.

doi:10.1103/physrevb.43.7395

Cited by 57 publications

(24 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A more difficult question concerns the nature of the localized electronic states. Some authors assume excess electrons to be localized on oxygen vacancies in analogy to the well-known F-centers in alkali halides whereas others suggest Zr3+-states in the lattice [9,19,21]. A possible way to decide this question could be the measurement of coupling coefficients between electron and oxide ion transport.…”

Section: Comparison With Literature Datamentioning

confidence: 97%

“…Most spectroscopic measurements involve UV-absorption-or reflection-spectroscopy [7, 13 -23, 271, some results were obtained from photoluminescence experiments [25]. Some other results on electronic defects were obtained from esr [19,26]. Whereas electrochemical measurements have been carried out at the temperatures of interest i.e.…”

Section: Comparison With Literature Datamentioning

confidence: 99%

See 1 more Smart Citation

Spectroscopy and Thermodynamics of Electrons in Yttria‐Stabilized Zirconia

Wiemhöfer

Vohrer

1992

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

Electronic energy gap, position of Fermi level in the gap and the density of states in the valence band range have been measured for Y203-stabilized cubic Zr02 as function of oxygen partial pressure and temperature using UV-Photoelectron-Spectroscopy (UPS) and Electron-Energy-Loss-Spectroscopy (EELS). A thermodynamic evaluation for the position of the Fermi energy gives the scale of electrode potentials for oxygen electrodes on stabilized zirconia with regard to the band scheme. The data are compared with further literature results from electrochemical and spectroscopic techniques and a model for the electronic band scheme of yttria-stabilized cubic zirconia is proposed. The differences of thermal and optical values for the band gap are discussed as well as the comparability of thermal and spectroscopic values for electronic energies.

show abstract

Section: Comparison With Literature Datamentioning

confidence: 97%

Section: Comparison With Literature Datamentioning

confidence: 99%

Spectroscopy and Thermodynamics of Electrons in Yttria‐Stabilized Zirconia

Wiemhöfer

Vohrer

1992

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

show abstract

“…In addition the electron paramagnetic resonance (EPR) spectrum of YSZ contains a prominent trigonal (T centre) peak in samples that have been chemically reduced or exposed to ionizing radiation [28][29][30][31] . This peak has been assigned to a vacancy-vacancy pair lying in a ⟨1 1 1⟩ direction neighbouring a Ti 3+ impurity 27,32,33 .…”

Section: Introductionmentioning

confidence: 99%

Chemical Descriptors of Yttria-Stabilized Zirconia at Low Defect Concentration: An ab Initio Study

et al. 2015

View full text Add to dashboard Cite

Keywords: solid oxide fuel cell, yttria stabilised zirconia, cubic zirconia, bixbyite yttria, ab initio, density functional theory, empirical potential, Born-Mayer-Huggins, point charge model, phonons, harmonic approximation. been observed in either X-ray or neutron diffraction experiments. The prediction of local defect structure and the interaction between defects is therefore of great interest. This has not been possible to date as the number of possible defect topologies is very large and to perform reliable total energy calculations for all of them would be prohibitively expensive. Previous theoretical studies have only considered a selection of representative structures. In this study, a comprehensive search for low energy defect structures using a combined classical modelling and density functional theory approach is used to identify the low energy isolated defect structures at the dilute limit, 3.2mol%. Through analysis of energetics computed using the best available Born-Mayer-Huggins empirical potential model, a point charge model, DFT, and a local strain energy estimated in the harmonic approximation, the main chemical and physical descriptors that correlate to the low energy DFT structures are discussed. It is found that the empirical potential model reproduces a general trend of increasing DFT energetics across a series of locally strain relaxed structures, but is unreliable both in predicting some incorrect low energy structures, and 3 in finding some meta-stable structures to be unstable. A better predictor of low energy defect structures is found to be the total electrostatic energy of a simple point charge model calculated at the unrelaxed geometries of the defects. In addition, the strain relaxation energy is estimated effectively in the harmonic approximation to the imaginary phonon modes of undoped c-ZrO 2 , but is found to be unimportant in determining the low energy defect structures. These results allow us to propose a set of easily computed descriptors that can be used to identify the low energy YSZ defect structures, negating the combinatorial complexity and number of defect structures that need to be considered. Abstract

show abstract

“…The typical result of this material . Thus optical spectroscopy [3][4][5][6], procedure is a tongue-shaped blackened region in the EPR measurements [6][7][8][9][10][11][12][13][14][15][16][17][18], conductivity measurecenter of the specimen since the surfaces of the ments [1,6,19,20], electron microscopy [21], X-ray specimen can still act as oxygen sources. Essentially, studies [7], dielectric measurements [22] and meathe activity of oxygen in the reduced material is surements of elastic properties [23,24] were percontrolled kinetically rather than thermodynamically.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical blackening of yttria-stabilized zirconia â morphological instability of the moving reaction front

1999

View full text Add to dashboard Cite

Electrochemical reduction was performed on both polycrystals of calcia-stabilized zirconia (CSY) and single crystals of yttria-stabilized zirconia (YSZ) at 5008C. A glass-encapsulation was used to prevent access of molecular oxygen from the gas phase and to realize a virtually two-dimensional geometry for the reacting crystal. The resulting blackening process which occurs by the advancement of a morphologically unstable reaction front was observed in-situ in a heating-stage by the use of an optical microscope.

show abstract

ESR centers in reduced stabilized zirconia

Cited by 57 publications

References 10 publications

Spectroscopy and Thermodynamics of Electrons in Yttria‐Stabilized Zirconia

Spectroscopy and Thermodynamics of Electrons in Yttria‐Stabilized Zirconia

Chemical Descriptors of Yttria-Stabilized Zirconia at Low Defect Concentration: An ab Initio Study

Electrochemical blackening of yttria-stabilized zirconia â morphological instability of the moving reaction front

Contact Info

Product

Resources

About

ESR centers in reduced stabilized zirconia

Cited by 57 publications

References 10 publications

Spectroscopy and Thermodynamics of Electrons in Yttria‐Stabilized Zirconia

Spectroscopy and Thermodynamics of Electrons in Yttria‐Stabilized Zirconia

Chemical Descriptors of Yttria-Stabilized Zirconia at Low Defect Concentration: An ab Initio Study

Electrochemical blackening of yttria-stabilized zirconia â morphological instability of the moving reaction front

Contact Info

Product

Resources

About

Electrochemical blackening of yttria-stabilized zirconia â morphological instability of the moving reaction front