Laurea Magistrale in Scienza dei Materiali. Materiali Inorganici Funzionali. Electrolytes: Ceria
|
|
- Hannah Peters
- 6 years ago
- Views:
Transcription
1 Laurea Magistrale in Scienza dei Materiali Materiali Inorganici Funzionali Electrolytes: Ceria Prof. Antonella Glisenti - Dip. Scienze Chimiche - Università degli Studi di Padova
2 Bibliography 1. N.Q. Minh, T. Takahashi: Science and technology of ceramic fuel cells Elsevier M. Mogensen et al. Solid State Ionics 129 (2000) H. Inaba et al. Solid State Ionics 83 (1996) V.V. Kharton et al. J. Mat. Science 36 (2001)
3 Electrical conductivity of fluoride-type oxides
4 Pure CeO 2 = pale yellow The ceria structure is known to tolerate a considerable reduction without phase change, especially at elevated temperatures. Such ceria is blue and turns almost black when grossly nonstoichiometric. The colour of CeO 2 is also sensitive to the presence of other lanthanides. 0.02% of Pr results in a brownish-yellow colour
5 Ceria Pure CeO 2 = cubic fluorite structure up to its melting point (does not need any stabilization) Depending on T and P O2 ceria exhibits a large oxygen deficiency with the formula CeO 2-δ (δ as large as 0.3). For small oxygen deficiencies (δ < 0.001) doubly ionized oxygen vacancies are the principal ionic defects, for large oxygen deficiencies a transition toward singly ionized vacancies has been observed pure ceria = n-type electrical conduction; ionic conductivity is negligible Ce 4+ ion radius is sufficiently large: a variety of dopant can be incorporated Ceria doped with divalent or trivalent oxides shows relatively high oxygen-ion conductivity at elevated temperatures: compared to YSZ shows a higher conductivity and a lower conduction activation energy
6 Ceria reduction Ceria undergoes reduction (to Ce III) at low P O2 : this restricts the range of O 2 partial pressure CeO 2-x The process of ceria reduction Oxide vacancies may also be introduced by doping with oxides of metals with lower valencies, e.g., by dissolution of CaO or Gd 2 O 3 : Oxide vacancies may be removed by doping with oxides of higher valencies: Law of mass action [Ce Ce ] = 2x [V O ] = x Undoped ceria [Ce Ce ] = 2x [V O ] = constant Doped ceria
7 Defects Association The theory of non-interactingdefects predicts an n-value of 6 The high n-values are not explainable in terms of non-interacting defects Discrete ordering phases separated by two-phase regions G O2 = RT ln P O2 Relative partial free energies, G, at 1100 C of CeO as a function of composition (log x)
8 1950s Brauer and Gradinger phases CeO 1.812, CeO 1.782, and CeO 1.719, formed as a result of ordering in the cation and anion sublattices. Bevan = δ-phase, Ce 11 O 20 (rhombohedral symmetry, exists over a broad composition range) ceria can be reduced to nonstoichiometric compositions, CeO 2-x, where x 2. Ce n O 2n-2 Four distinct phases corresponding to n = 7 (1.74), 9 (1.79), 10 (1.8) and 11 (1.818). Riess Phase Diagram.
9 n = n = n = 4 n = 5 Diagram of subregions with possible ordered intermediate phases in the α-phase for the cerium oxygen system
10 Molar Volume Changes in the molar volume of CeO 2-x vs. composition for the transformation α+δ α+α and α+δ α +δ (sx) on heating; (dx) on cooling Undercooling during temperature decrease
11 Kim Conductivity and dopant ion radius the nonstoichiometry may be regarded as a simple solid solution of Ce 2 O 3 in CeO 2. lattice parameter should follow Vegard s rule, i.e., a linear relationship exists between lattice parameter and the concentration of the solute. The slope of this straight line is termed Vegard s slope. a (nm) = lattice constant of ceria r (nm) is the difference in ionic radius of the kth dopant Ce 4+ -radius (eightfold coordination) is nm according to Shannon z k is the valence (z k - 4) m k = mole percent of the k th dopant in the form of MO 2. Ce 2 O 3 Ln 2 O 3
12 Ceria reduction as a doping Kim Percent expansion of cerium dioxide versus nonstoichiometric composition at 900 C. (- - -) Theoretical slope; ( ) best fit slope. Expansion: Ce(III) ion radius is bigger than Ce(IV) Oxide vacancy radius = nm (RT)
13 Solubility of other oxides and change in lattice parameters Kim: the solubility limit of a solute depends on the elastic energy, W, which is introduced in the lattice due to differences in ionic radius. The larger the elastic energy per substituted ion, the lower is the solubility. a 0 (nm) = lattice constant of ceria a (nm) change in lattice parameter (governed by Vegard s slope) G shear modulus CRITICAL RADIUS = radius giving a Vegard s slope of zero ( to nm)
14 Determination of the critical ionic radius r. The y- axis is the slopes of each individual lattice parameter as a function of dopant concentration, x.
15 Doped ceria Used dopants: La 2 O 3, Y 2 O 3, Sm 2 O 3, Gd 2 O 3, Gd 2 O 3 +Pr 2 O 3, CaO, SrO Arrhenius plots of ionic conductivities of doped ceria compounds
16 Conductivity and dopant ion radius The ionic conductivity increases with increasing ionic radius, from Yb to Sm, but decreased at r > nm. (CeO 2 ) 0.8 (LnO 1.5 ) 0.2 as a function of radius of dopant ion. Ce(IV) = 128 pm Ce(III) = 111 pm Ionic conductivity of doped ceria
17 Doped ceria Sm 3+ among the rare earth oxide and Ca 2+ among alkaline earth = maximum electrical conductivity Ionic conductivity of doped ceria at 1073 K against the radius of dopant cation In the horizontal axis the critical radius of M 2+ and M 3+ The maximum electrical conductivity is due to the similar ionic radius as the host ion = minimum association entalpy between dopant ion and oxygen vacancy
18 Mg, Ba - Doped ceria The electrical conductivities when doping with MgO and BaO are exceptionally low = insufficient solubility of these oxides in ceria. Sm Sr Ca Ba Mg Lattice constants of ceria based oxides (CeO 2 ) 1-x (MO y ) x as a function of dopant concentration, x
19 Conductivity and dopant ion radius CeO 2 -Ln 2 O 3 1. Conductivities are higher for different concentrations depending on the dopant 2. The minimum E att depends on dopant cations Low T activation entalpy and electrical conductivity of Y- doped ceria as a function of dopant concentration There are some interactions between dopant ions and oxygen vacancies Activation energy against dopant concentration for various rare earthdoped cerias
20 Conductivity and dopant ion radius 1. Difetti liberi 2. Difetti carichi 3. Difetti neutri CeO 2-x x < 10-3 CeO 2-x 10-3 < x < 10-2 CeO 2-x 10-3 x > 10-2
21 Butler et al. and Catlow modelled the effect of the dopant ion radius on the dopant vacancy interaction in CeO 2, and thus on the ionic conductivity. Calculated binding energy of oxide vacancies: an oxygen vacancy with one, two, three and four nearest neighbour dopant ions for dopant ions with different ion size and charge.
22 Free Vacancies A 1, A 2, Associative m = Migration W = number of orientation of the associate C M = total dopant concentration Uncharged Associated Defects Dopant cation radius Low Order Double Doping Charged Associated Defects
23 Conductivity and dopant ion radius MO 2 -Ln 2 O 3
24 Grain Boundary Conductivity Strong influence of the preparation procedure Some grain boundary resistance is most often seen even in high purity material, especially at low temperature Plot of σt versus 1/T for the CeO :0.3% CaO sample 1. amorphous glassy phase in the grain boundaries caused by impurities. 2. microporosity in the boundaries 3. segregation of the dopant ions. Bulk conductivity Bulk conductivity + Grain Boundary
25 Grain Boundary Conductivity Doping reduces the effect of grain boundary (dopant segregation) Bulk Total Total Total Bulk Plot of σt versus 1/T for the CeO 2 : 0.3% CaO sample Segregation of high-resistivity phases Doping extraction from bulk toward surface: grains become practically undoped (micron grains) Plot of σt versus 1/T for the CeO 2 : 15% CaO sample
26 GBC and sintering temperature Complex impedance spectra of CGO20 ceramics sintered in air at 1873 (open simbols) and 1773 K for 2 hours (full simbols). SEM micrographs of CGO20 ceramics sintered in air at 1873 (A) and 1773 K (B) for 2 hours.
27 T dependence of the total conductivity in air: (A) CGO20 and CGO20- based ceramics, (B) CGO10 and CGO10-based ceramics. Small additions of several cations seem to be ineffective, probably due to segregation of dopants at the grain boundaries
28
29 Doped ceria electrical conductivity increases at low oxygen partial pressures Electrolytic Domain? Conductivity of doped ceria as a function of oxygen partial pressure
30 Doped ceria reduction The reduction (i.e. the electronic conductivity) of doped ceria under reducing atmospheres can be minimized by modifying the dopant: Another possibility is to suppress the reduction of ceria by coating the solid with a film of a more stable ionic conducting compound (CeO 2 ) 0.8 (Sm 2 O 3 ) 0.2 coated with a YSZ thin film (2 µm) on the fuel side produced a stable SOFC electrolyte Electrolytic and ionic domain boundaries of doped ceria Conductivities of (ZrO 2 ) 0.9 (Y 2 O 3 ) 0.10 as a function of oxygen partial pressure
31 Doped ceria reduction The replacement of 3%mol Gd by Pr in Ce 0.8 Gd 0.2 O 2-δ improves the electrolytic domain of the material by nearly two orders of magnitude without significantly affecting ionic conductivity. Temperature dependence of the electrolytic domain boundary of CeO 2 -based electrolytes at low oxygen pressures.
32 The chemical compatibility?
33 At temperatures <1000 C (operating T) = little interfacial phase formation. At higher temperatures (fabrication)... Ce 1-x Gd x O 2-y with 8YSZ Reaction after heat treatment at 1300 C for 72 h: formation of a cubic-like phase Ni/YSZ anode + Ce(Gd)O 2-y electrolyte sintered at 1300 C = formation of Gd 2 Zr 2 O 7 and Gd 2 NiO 4 : high resistivity & poor cell performance Chromium based interconnects/gd doped ceria: No reaction between (La,Sr)CrO 3 and Ce 0.8 Gd 0.3 O 1.9 at 1600 C. SrCrO 4 reacted with CGO via a Sr Cr O liquid phase forming an unknown phase at the interface and grain boundaries, consisting of Ce, Sr, Gd and Cr. CaCrO 4 reacted with CGO via a liquid Ca Cr O phase, transforming CGO grains into an unknown phase. Cr 2 O 3 compatible with CGO for temperatures below 1400 C in air.
34 In general, fracture of ceramics is caused by flaws originating from the fabrication, and thus, the fabrication method is of most importance. YSZ Bonding Strength = MPa YSZ Fracture Toughnes = 3MPa m 1/2
Electrolytes: Stabilized Zirconia
Laurea Magistrale in Scienza dei Materiali Materiali Inorganici Funzionali Electrolytes: Stabilized Zirconia Prof. Antonella Glisenti - Dip. Scienze Chimiche - Università degli Studi di Padova Bibliography
More informationLaurea Magistrale in Scienza dei Materiali. Materiali Inorganici Funzionali. Electrolytes: Stabilized bismuthsesquioxide
Laurea Magistrale in Scienza dei Materiali Materiali Inorganici Funzionali Electrolytes: Stabilized bismuthsesquioxide Prof. Antonella Glisenti - Dip. Scienze Chimiche - Università degli Studi di Padova
More informationElectrical conduction in ceramics
Laurea Magistrale in Scienza dei Materiali Materiali Inorganici Funzionali Electrical conduction in ceramics Prof. Antonella Glisenti - Dip. Scienze Chimiche - Università degli Studi di Padova Conductivity
More informationChapter 4. Ionic conductivity of GDC. electrolyte
Chapter 4 Ionic conductivity of GDC electrolyte 4.1 Introduction Solid oxides with fluorite structure, such as, ZrO 2 and CeO 2, when doped with aliovalent cations become oxygen ion conductor and are used
More informationSOFCs Components: cathodes
Laurea Magistrale in Scienza dei Materiali Materiali Inorganici Funzionali SOFCs Components: cathodes Prof. Antonella Glisenti - Dip. Scienze Chimiche - Università degli Studi di Padova Cathode: requirements
More informationSOFCs Components: anodes
Laurea Magistrale in Scienza dei Materiali Materiali Inorganici Funzionali SOFCs Components: anodes Prof. Antonella Glisenti - Dip. Scienze Chimiche - Università degli Studi di Padova Bibliography 1. N.Q.
More informationChapter 7. Evaluation of Electrode Performance by. Electrochemical Impedance
Chapter 7 Evaluation of Electrode Performance by Electrochemical Impedance Spectroscopy (EIS) 7.1 Introduction A significant fraction of internal resistance of a cell comes from the interfacial polarization
More informationPHYSICAL PROPERTIES OF La 0.9 Sr 0.1 Cr 1-X Ni X O 3-δ (X = 0-0.6) SYNTHESIZED VIA CITRATE GEL COMBUSTION
PHYSICAL PROPERTIES OF La 0.9 Sr 0.1 Cr 1-X Ni X O 3-δ (X = 0-0.6) SYNTHESIZED VIA CITRATE GEL COMBUSTION Anuchit Ruangvittayanon * and Sutin Kuharuangrong Received: Sept 29, 2009; Revised: Nov 17, 2009;
More informationIonic Conductivity and Solid Electrolytes II: Materials and Applications
Ionic Conductivity and Solid Electrolytes II: Materials and Applications Chemistry 754 Solid State Chemistry Lecture #27 June 4, 2003 References A. Manthiram & J. Kim Low Temperature Synthesis of Insertion
More informationImperfections, Defects and Diffusion
Imperfections, Defects and Diffusion Lattice Defects Week5 Material Sciences and Engineering MatE271 1 Goals for the Unit I. Recognize various imperfections in crystals (Chapter 4) - Point imperfections
More informationLaurea in Scienza dei Materiali Materiali Inorganici Funzionali. Electrolyzers
Laurea in Scienza dei Materiali Materiali Inorganici Funzionali Electrolyzers Prof. Dr. Antonella Glisenti -- Dip. Scienze Chimiche -- Università degli Studi di di Padova H 2 by Electrolysis High purity
More informationChapter 3. Synthesis and characterization. of GDC electrolyte material
Chapter 3 Synthesis and characterization of GDC electrolyte material 3.1 Introduction Ceria based oxide materials are used as electrolytes for intermediate temperature solid oxide fuel cell (IT-SOFC) applications.
More informationDefects and Diffusion
Defects and Diffusion Goals for the Unit Recognize various imperfections in crystals Point imperfections Impurities Line, surface and bulk imperfections Define various diffusion mechanisms Identify factors
More informationHigh Conductivity Oxides for Solid Oxide Fuel Cells ABEL FERNANDEZ MATERIALS 286G JUNE 2016
High Conductivity Oxides for Solid Oxide Fuel Cells ABEL FERNANDEZ MATERIALS 286G JUNE 2016 How do Solid Oxide Fuel Cells Work? O 2 O 2 O 2 O 2 Cathode Electrolyte O 2- O 2- O 2- Porous cathode reduces
More informationa) The self-diffusion coefficient of a metal with cubic structure can be expressed as
EXERCISES KJM5120 Chapter 5; Diffusion 1. Random (self) diffusion a) The self-diffusion coefficient of a metal with cubic structure can be expressed as 1 n D = s 6 t 2 where n/t represents the jump frequency
More informationThermodynamic studies of oxidation and reduction of ceria and ceria mixed oxides
Thermodynamic studies of oxidation and reduction of ceria and ceria mixed oxides R. J. Gorte Chemical & Biomolecular Engineering University of Pennsylvania Support: DOE-BES Collaborators: Paolo Fornasiero,
More informationInfluence of Rare Earths on the Sintering of Zirconia-Yttria. Experimental
Materials Research, Vol. 2, No. 3, 211-217, 1999. 1999 Influence of Rare Earths on the Sintering of Zirconia-Yttria I.C. Canova a, D.P.F. de Souza a#, N.R. Costa a, M.F. de Souza b a Departamento de Engenharia
More informationCHAPTER 8 CONCLUSIONS AND SUGGESTIONS FOR FUTURE WORK
CHAPTER 8 CONCLUSIONS AND SUGGESTIONS FOR FUTURE WORK 8.1. Conclusions Referring to the aims of the research project in Chapter 4, the following conclusions can be drawn on the basis of the present work:
More informationSome structural aspects of ionic conductivity in zirconia stabilised by yttria and calcia
Materials Science-Poland, Vol. 24, No. 1, 2006 Some structural aspects of ionic conductivity in zirconia stabilised by yttria and calcia M. M. BUĆKO * AGH University of Science and Technology, Faculty
More informationMechanisms of Diffusion II. Ionic Crystals L5 11/3/03-1-
Mechanisms of Diffusion II. Ionic Crystals 3.05 L5 11/3/03-1- Charges on point imperfections Point imperfections in ionic crystals are generally electrically charged. 3.05 L5 11/3/03 - (a) Unit cell in
More informationCONDUCTIVITY AND STABILITY OF BISMUTH OXIDE-BASED ELECTROLYTES AND THEIR APPLICATIONS FOR IT-SOFCS
CONDUCTIVITY AND STABILITY OF BISMUTH OXIDE-BASED ELECTROLYTES AND THEIR APPLICATIONS FOR IT-SOFCS By DOH WON JUNG A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL
More informationElectrical Property of Thick Film Electrolyte for Solid Oxide Fuel Cell
Journal of Metals, Materials and Minerals, Vol.18 No.2 pp.7-11, 28 Electrical Property of Thick Film Electrolyte for Solid Oxide Fuel Cell Thitimaporn DUANGMANEE 1, Suda WANNAKITTI 2, Rapeepong SUWANWARANGKUL
More informationEffect of Rare Earth Oxide Coating in Improving the Cyclic Oxidation Resistance of Chromia Forming Alloys
Effect of Rare Earth Oxide Coating in Improving the Cyclic Oxidation Resistance of Chromia Forming Alloys S.M.C.Fernandes and L.V.Ramanathan Instituto de Pesquisas Energéticas e Nucleares (IPEN) Av. Prof.
More informationDevelopment of Ceria-Zirconia Solid Solutions and Future Trends
Special Issue Oxygen Storage Materials for Automotive Catalysts Ceria-Zirconia Solid Solutions 1 Review Development of Ceria-Zirconia Solid Solutions and Future Trends Hideo Sobukawa This review summarizes
More informationMSE 351 Engineering Ceramics I
Kwame Nkrumah University of Science & Technology, Kumasi, Ghana MSE 351 Engineering Ceramics I Ing. Anthony Andrews (PhD) Department of Materials Engineering Faculty of Mechanical and Chemical Engineering
More informationCeramics for Energy Storage and Conversion. Dr. Doreen Edwards Dean of Engineering Prof. of Materials Science & Engineering
Ceramics for Energy Storage and Conversion Dr. Doreen Edwards Dean of Engineering Prof. of Materials Science & Engineering Ceramic and Glass Materials are Critical to Energy Storage and Conversion Devices
More informationElectrical Properties of Co-Doped Ceria Electrolyte Ce 0.8 x Gd 0.2 Sr x O 2 δ (0.0 x 0.1)
Vol. 115 (2009) ACTA PHYSICA POLONICA A No. 5 Electrical Properties of Co-Doped Ceria Electrolyte Ce 0.8 x Gd 0.2 Sr x O 2 δ (0.0 x 0.1) S. Ramesh and C. Vishnuvardhan Reddy Department of Physics, University
More informationDevelopment of Novel Anode Material for Intermediate Temperature SOFC (IT-SOFC)
Development of Novel Anode Material for Intermediate Temperature SOFC (IT-SOFC) Amit Sinha *, D. N. Miller and J.T.S. Irvine School of Chemistry, University of St Andrews North Haugh, St Andrews KY16 9ST
More informationPEROVSKITES FOR USE AS SULFUR TOLERANT ANODES. A dissertation submitted to the. Graduate School. Of the University of Cincinnati
PEROVSKITES FOR USE AS SULFUR TOLERANT ANODES A dissertation submitted to the Graduate School Of the University of Cincinnati In partial fulfillment on the Requirements for the degree of Doctor of Philosophy
More informationSOFC Cathodes, Supports and Contact Layers. Alan Atkinson Department of Materials Imperial College London SW7 2AZ, UK
SOFC Cathodes, Supports and Contact Layers Alan Atkinson Department of Materials Imperial College London SW7 2AZ, UK alan.atkinson@imperial.ac.uk Contents for cathodes Requirements for application in SOFCs
More informationA great many properties of crystals are determined by imperfections.
Defect in ceramics A great many properties of crystals are determined by imperfections. Electrical conductivity Diffusion transport imperfection Optical properties Rate of kinetic process Precipitation
More informationThe characteristics of nano-sized Gd-doped CeO 2 particles prepared by spray pyrolysis
Journal of Alloys and Compounds 398 (2005) 240 244 The characteristics of nano-sized Gd-doped CeO 2 particles prepared by spray pyrolysis Hee Sang Kang a, Jong Rak Sohn b, Yun Chan Kang c,, Kyeong Youl
More informationElectrical Properties and Defect Structure of Praseodymium-Cerium Oxide Solid Solutions. Todd Stanley Stefanik. BS Ceramic Engineering
Electrical Properties and Defect Structure of Praseodymium-Cerium Oxide Solid Solutions by Todd Stanley Stefanik BS Ceramic Engineering New York State College of Ceramics at Alfred University, 1995 SM
More informationCHAPTER INTRODUCTION
CHAPTER 4 EFFECT OF ALKALINE EARTH METAL AND TRANSITION METAL DOPANTS ON THE STRUCTURAL, OPTICAL AND ELECTRONIC PROPERTIES OF YTTRIUM STABILIZED ZIRCONIA NANOPARTICLES 4.1 INTRODUCTION The tetragonal and
More informationCHAPTER 5 IMPERFECTIONS IN SOLIDS PROBLEM SOLUTIONS
CHAPTER 5 IMPERFECTIONS IN SOLIDS PROBLEM SOLUTIONS Vacancies and Self-Interstitials 5.1 Calculate the fraction of atom sites that are vacant for copper at its melting temperature of 1084 C (1357 K). Assume
More informationSOFC Powders and Unit Cell Research at NIMTE. Jian Xin Wang, Jing Shao, You Kun Tao, Wei Guo Wang
595 10.1149/1.3205571 The Electrochemical Society SOFC Powders and Unit Cell Research at NIMTE Jian Xin Wang, Jing Shao, You Kun Tao, Wei Guo Wang Division of Fuel Cell and Energy Technology Ningbo Institute
More informationE45 Midterm 01 Fall 2007! By the 0.2% offset method (shown on plot), YS = 500 MPa
1.!Mechanical Properties (20 points) Refer to the following stress-strain plot derived from a standard uniaxial tensile test of a high performance titanium alloy to answer the following questions. Show
More informationAdvanced materials for SOFCs
Advanced materials for SOFCs Yoed Tsur Department of Chemical Engineering Technion Outline Intro: why SOFCs are important? Types of SOFCs Hybrid SOFC-something for power generation: NG utilization Materials
More informationNovel Mn 1.5 Co 1.5 O 4 spinel cathodes for intermediate temperature solid oxide fuel cells
Novel Mn 1.5 Co 1.5 O 4 spinel cathodes for intermediate temperature solid oxide fuel cells Huanying Liu, a, b Xuefeng Zhu, a * Mojie Cheng, c You Cong, a Weishen Yang a * a State Key Laboratory of Catalysis,
More informationCHAPTER 5 IMPERFECTIONS IN SOLIDS PROBLEM SOLUTIONS ev /atom = exp. kt ( =
CHAPTER 5 IMPERFECTIONS IN SOLIDS PROBLEM SOLUTIONS Vacancies and Self-Interstitials 5.1 Calculate the fraction of atom sites that are vacant for copper at its melting temperature of 1084 C (1357 K). Assume
More informationFuel Cell Research Activities at the University of Leoben Focus: Solid Oxide Fuel Cells. Werner Sitte
Fuel Cell Research Activities at the University of Leoben Focus: Solid Oxide Fuel Cells Werner Sitte Chair of Physical Chemistry, University of Leoben, Austria IEA Workshop Advanced Fuel Cells, TU Graz,
More informationGadolinia doped ceria/yttria stabilised zirconia electrolytes for solid oxide fuel cell applications
JOURNAL OF MATERIALS SCIENCE 39 (2004) 235 240 Gadolinia doped ceria/yttria stabilised zirconia electrolytes for solid oxide fuel cell applications Abstract J. LUO, R. J. BALL, R. STEVENS Materials Research
More informationRole of small amount of MgO and ZrO 2 on creep behaviour of high purity Al 2 O 3
Bull. Mater. Sci., Vol. 28, No. 3, June 2005, pp. 281 285. Indian Academy of Sciences. Role of small amount of MgO and ZrO 2 on creep behaviour of high purity Al 2 O 3 L N SATAPATHY* and S SWAROOP Ceramic
More informationENHANCED IONIC CONDUCTIVITY OF CERIA-BASED COMPOUNDS FOR THE ELECTROLYTE APPLICATION IN SOFCS
ENHANCED IONIC CONDUCTIVITY OF CERIA-BASED COMPOUNDS FOR THE ELECTROLYTE APPLICATION IN SOFCS By SHOBIT OMAR A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
More informationPoint Defects in Metals
CHAPTER 5 IMPERFECTIONS IN SOLIDS PROBLEM SOLUTIONS Point Defects in Metals 5.1 Calculate the fraction of atom sites that are vacant for lead at its melting temperature of 327 C (600 K). Assume an energy
More informationPhysics of Transition Metal Oxides
Physics of Transition Metal Oxides Lecture 11 Defects in oxides Defects in oxides: We have looked at a variety of defects already. Today we discuss structural defects, giving rise to distinct phases impurity
More informationConductivity of Sr, Na and Li Doped BaCeO 3
Journal of Metals, Materials and Minerals, Vol.2 No.3 pp.55-59, 21 Conductivity of Sr, Na and Li Doped Ba Siriwan CHOKKHA * and Sutin KUHARUANGRONG * School of Ceramic Engineering, Suranaree University
More informationCrystal Defects. Perfect crystal - every atom of the same type in the correct equilibrium position (does not exist at T > 0 K)
Crystal Defects Perfect crystal - every atom of the same type in the correct equilibrium position (does not exist at T > 0 K) Real crystal - all crystals have some imperfections - defects, most atoms are
More informationELECTRICAL AND THERMAL PROPERTIES OF YTTRIA-STABILISED ZIRCONIA (YSZ)-BASED CERAMIC MATERIALS. Doctor of Philosophy
ELECTRICAL AND THERMAL PROPERTIES OF YTTRIA-STABILISED ZIRCONIA (YSZ)-BASED CERAMIC MATERIALS A thesis submitted to The University of Manchester for the degree of Doctor of Philosophy in the Faculty of
More informationThe synthesis and characterization of alkaline-earth metal doped Pr 2 Mo 2 O 9 pigments: Applications in coloring of plastics
Chapter 4 The synthesis and characterization of alkaline-earth metal doped Pr 2 Mo 2 O 9 pigments: Applications in coloring of plastics Summary A new class of inorganic pigments based on praseodymium molybdate
More information1. Use the Ellingham Diagram (reproduced here as Figure 0.1) to answer the following.
315 Problems 1. Use the Ellingham Diagram (reproduced here as Figure 0.1) to answer the following. (a) Find the temperature and partial pressure of O 2 where Ni(s), Ni(l), and NiO(s) are in equilibrium.
More informationCHARACTARISTICS OF DAMAGE AND FRACTURE PROCESS OF SOLID OXIDE FUEL CELLS UNDER SIMULATED OPERATING CONDITIONS BY USING AE METHOD
CHARACTARISTICS OF DAMAGE AND FRACTURE PROCESS OF SOLID OXIDE FUEL CELLS UNDER SIMULATED OPERATING CONDITIONS BY USING AE METHOD KAZUHISA SATO 1), TOSHIYUKI HASHIDA 2), HIROO YUGAMI 3), KEIJI YASHIRO 1),
More informationEFFECT OF SOL-GEL PREPARATION TECHNIQUE OF MIXED NANOCRYSTALLINE RARE EARTH OXIDE COATINGS ON HIGH TEMPERATURE OXIDATION BEHAVIOR OF Fe20Cr5Al ALLOY.
EFFECT OF SOL-GEL PREPARATION TECHNIQUE OF MIXED NANOCRYSTALLINE RARE EARTH OXIDE COATINGS ON HIGH TEMPERATURE OXIDATION BEHAVIOR OF Fe20Cr5Al ALLOY. S.M.C.Fernandes, O.V.Correa, L.V.Ramanathan Instituto
More informationSTACK PERFORMANCE OF INTERMEDIATE TEMPERATURE-OPERATING SOLID OXIDE FUEL CELLS USING STAINLESS STEEL INTERCONNECTS AND ANODE-SUPPORTED SINGLE CELLS
Proceedings of FUELCELL25 Third International Conference on Fuel Cell Science, Engineering and Technology May 23-25, 25, Ypsilanti, Michigan FUELCELL25-715 STACK PERFORMANCE OF INTERMEDIATE TEMPERATURE-OPERATING
More informationDevelopment of LSCF: CGO Composite Cathodes for SOFCs by Suspension Spraying and Sintering
Development of LSCF: CGO Composite Cathodes for SOFCs by Suspension Spraying and Sintering R. Costa *, R. Spotorno, Z. Ilhan, A. Ansar German Aerospace Center, Institute of Technical Thermodynamics, Pfaffenwaldring
More informationOxygen ion diffusivity in strained yttria stabilized zirconia: where is the fastest strain?
PAPER www.rsc.org/materials Journal of Materials Chemistry Oxygen ion diffusivity in strained yttria stabilized zirconia: where is the fastest strain? Akihiro Kushima and Bilge Yildiz* Received 8th January
More informationElectrical conductivity and microstructure relationship in ternary systems based on cerium oxide
Available online at www.sciencedirect.com Ceramics International 39 (2013) 5887 5892 CERAMICS INTERNATIONAL www.elsevier.com/locate/ceramint Electrical conductivity and microstructure relationship in ternary
More informationChapter 3: Atomic and Ionic Arrangements. Chapter 3: Atomic and Ionic Arrangements Cengage Learning Engineering. All Rights Reserved.
Chapter 3: Atomic and Ionic Arrangements 3-1 Learning Objectives 1. 2. 3. 4. 5. 6. 7. 8. Short-range order versus long-range order Amorphous materials Lattice, basis, unit cells, and crystal structures
More informationFabrication of Calcium Doped PlSZT Ceramics using High Planetary Mill Method
Journal of Physics: Conference Series PAPER OPEN ACCESS Fabrication of Calcium Doped PlSZT Ceramics using High Planetary Mill Method To cite this article: T.N. I. Tuan Ab Rashid et al 2018 J. Phys.: Conf.
More informationElement diffusion in SOFCs: multi-technique characterization approach
Degradation mechanisms and advanced characterization and testing (II) Element diffusion in SOFCs: multi-technique characterization approach M. Morales 1, A. Slodczyk 1, A. Pesce 2, A. Tarancón 1, M. Torrell
More informationPreparation and characterization of metal supported solid oxide fuel cells with screen-printed electrodes and thin-film electrolyte
Preparation and characterization of metal supported solid oxide fuel cells with screen-printed electrodes and thin-film electrolyte Feng HAN 1 *, Robert SEMERAD 2, Patric SZABO 1, Rémi COSTA 1 feng.han@dlr.de
More informationAll-solid-state Li battery using a light-weight solid electrolyte
All-solid-state Li battery using a light-weight solid electrolyte Hitoshi Takamura Department of Materials Science, Graduate School of Engineering, Tohoku University Europe-Japan Symposium, Electrical
More informationSYNTHESIS AND ELECTRICAL PROPERTIES OF Sr 3 NiNb 2 O 9 MATERIALS FOR SOFCs
Journal of Ovonic Research Vol. 12, No. 2, March April 2016, p. 81-86 SYNTHESIS AND ELECTRICAL PROPERTIES OF MATERIALS FOR SOFCs Q. LI *, Z. P. LIU, R. YAN, L. M. DONG College of Materials Science and
More informationatoms g/mol
CHAPTER 2 ATOMIC STRUCTURE 2 6(a) Aluminum foil used for storing food weighs about 0.05 g/cm². How many atoms of aluminum are contained in this sample of foil? In a one square centimeter sample: number
More informationOxygen Diffusion in Bi 2 O 3
Materials Research, Vol. 11, No. 2, 221-225, 2008 2008 Oxygen Diffusion in Antônio Claret Soares Sabioni a *, Antônio Márcio J.M. Daniel a, Wilmar Barbosa Ferraz b, Rafael Witter Dias Pais a, Anne-Marie
More informationStructural Properties of NiO-CGO Composites Precursor Prepared via Combustion Synthesis Route
Asian Journal of Chemistry Vol. 21, No. 10 (2009), S157-161 Structural Properties of NiO-CGO Composites Precursor Prepared via Combustion Synthesis Route PANKAJ KALRA# ANIRUDH P. SINGH and AJAY KUMAR #
More informationOxidation Reactions. This oxide will from only if thermodynamics favour a reaction of the form: M + O 2 = MO 2. Which must form rapidly (favourable(
Oxidation of s Oxidation is a general term used to define the reaction between a metal or alloy and its environment. s or alloys are oxidised when heated to elevated temperatures es in air or highly oxidised
More informationLab 1 The Defect Structure of cubic Bi 2 O 3 Nb 2 O 5 Solid Solutions
Lab 1 The Defect Structure of cubic Bi 2 O 3 Nb 2 O 5 Solid Solutions 27-202 Fall 2002 Objective The objective of this lab is to identify the defect structure and charge compensation mechanism in Bi 2
More informationBulk Diffusion in Alumina: Solving the Corundum Conundrum
Bulk Diffusion in Alumina: Solving the Corundum Conundrum Nicholas D.M. Hine 1,2,3 K. Frensch 3, W.M.C Foulkes 1,2, M.W. Finnis 2,3, A. H. Heuer 3,4 1 Theory of Condensed Matter Group, Cavendish Laboratory,
More informationApplication of INAA for Aluminium Magnesium Oxide Materials Investigation
Application of INAA for Aluminium Magnesium Oxide Materials Investigation D. Riekstina, O. Veveris, V. Skvortsova, Institute of Solid State Physics, University of Latvia APPLICATIONS T melt = 2800ºC ccubic
More informationCeramic Processing Research
Journal of Ceramic Processing Research. Vol. 11, No. 4, pp. 460~464 (2010) J O U R N A L O F Ceramic Processing Research Redox equilibrium of Fe 3+ /Fe 2+ and diffusivity of iron in alkali-alkaline earth-silicate
More informationDefect in crystals. Primer in Materials Science Spring
Defect in crystals Primer in Materials Science Spring 2017 11.05.2017 1 Introduction The arrangement of the atoms in all materials contains imperfections which have profound effect on the behavior of the
More informationStructural Properties of Zirconia Doped with Some Oxides
The Open-Access Journal for the Basic Principles of Diffusion Theory, Experiment and Application www..org, ISSN 1862-4138; 2005-2008 Structural Properties of Zirconia Doped with Some Oxides Hussien Ahmed
More informationNanocrystalline Rare Earth Oxide Coatings for Increased Protection of Iron-chromium Alloys at High Temperatures
Proceedings of the 5 th International Conference on Nanotechnology: Fundamentals and Applications Prague, Czech Republic, August 11-13, 2014 Paper No. 40 Nanocrystalline Rare Earth Oxide Coatings for Increased
More informationSummary Chapter Chapter Chapter
Ceria (CeO 2 ) has been extensively employed as an important component of automotive three-way catalysts (TWC) for reducing the exhaust pollutants. Besides this, fuel cell processes, oxygen permeation
More informationChapter 12: Structures & Properties of Ceramics
Chapter 12: Structures & Properties of Ceramics ISSUES TO ADDRESS... Review of structures for ceramics How are impurities accommodated in the ceramic lattice? In what ways are ceramic phase diagrams similar
More informationOxide-ion conductors for fuel cells
Materials Science-Poland, Vol. 24, No. 1, 2006 Oxide-ion conductors for fuel cells F. KROK 1*, I. ABRAHAMS 2**, W. WROBEL 1, A. KOZANECKA-SZMIGIEL 1, J. R. DYGAS 1 1 Faculty of Physics, Warsaw University
More informationTitle: The synthesis and characterization of PVP coated cerium oxide nanoparticles.
Supporting Information. Title: The synthesis and characterization of PVP coated cerium oxide nanoparticles. Authors: Ruth C. Merrifield 1, Zhiwei Wang 2, Richard E. Palmer 2, Jamie R. Lead 1 * 1 School
More informationHigh-resolution electron microscopy of grain boundary structures in yttria-stabilized cubic zirconia
Mat. Res. Soc. Symp. Proc. Vol. 654 2001 Materials Research Society High-resolution electron microscopy of grain boundary structures in yttria-stabilized cubic zirconia K. L. Merkle, L. J. Thompson, G.-R.
More informationNPTEL COURSE ADVANCED CERAMICS FOR STRATEGIC APPLICATIONS QUESTIONS AND ANSWERS
NPTEL COURSE ADVANCED CERAMICS FOR STRATEGIC APPLICATIONS QUESTIONS AND ANSWERS Q1: What do you understand by Ceramics? Ans: Ceramics are a group of chemical compounds, either simple (consisting of only
More informationHigh Thermal Conductivity Silicon Nitride Ceramics
Journal of the Korean Ceramic Society Vol. 49, No. 4, pp. 380~384, 2012. http://dx.doi.org/10.4191/kcers.2012.49.4.380 Review High Thermal Conductivity Silicon Nitride Ceramics Kiyoshi Hirao, You Zhou,
More informationCHAPTER 4: Oxidation. Chapter 4 1. Oxidation of silicon is an important process in VLSI. The typical roles of SiO 2 are:
Chapter 4 1 CHAPTER 4: Oxidation Oxidation of silicon is an important process in VLSI. The typical roles of SiO 2 are: 1. mask against implant or diffusion of dopant into silicon 2. surface passivation
More informationFUEL CELL CHARGE TRANSPORT
FUEL CELL CHARGE TRANSPORT M. OLIVIER marjorie.olivier@fpms.ac.be 19/05/2008 INTRODUCTION Charge transport completes the circuit in an electrochemical system, moving charges from the electrode where they
More informationSupplementary Figure 1 X-ray photoelectron spectroscopy profile of Nb and Ta of SCNT at room temperature.
Supplementary Figure 1 X-ray photoelectron spectroscopy profile of Nb and Ta of SCNT at room temperature. Supplementary Figure 2 Factors that may affect the area specific resistance of SCNT cathode. (a)
More informationDesign of Higher-k and More Stable Rare Earth Oxides as Gate Dielectrics for Advanced CMOS Devices
Materials 2012, 5, 1413-1438; doi:10.3390/ma5081413 Review OPEN ACCESS materials ISSN 1996-1944 www.mdpi.com/journal/materials Design of Higher-k and More Stable Rare Earth Oxides as Gate Dielectrics for
More informationThe Nernst-Einstein equation indicates that the ratio β /D for a given material varies only with temperature. Calculate β/d for oxygen ions in Zr 0.
The Nernst-Einstein equation indicates that the ratio β /D for a given material varies only with temperature. Calculate β/d for oxygen ions in 0.8 Y 0.2 1.9 at 800 C. 1 The Nernst-Einstein equation indicates
More informationThe mechanical and electrical properties of Ni/YSZ anode support for solid oxide fuel cells
The mechanical and electrical properties of Ni/YSZ anode support for solid oxide fuel cells Changrong He, Tao Chen, Wei Guo Wang Ningbo Institute of Material Technology and Engineering (NIMTE), Chinese
More informationSUPPLEMENTARY INFORMATION
High Electrochemical Activity of the Oxide Phase in Model Ceria- and Ceria-Ni Composite Anodes William C. Chueh 1,, Yong Hao, WooChul Jung, Sossina M. Haile Materials Science, California Institute of Technology,
More informationAl2O3-MgO system: magnesia and spinel Magnesia
Al 2 O 3 -MgO system: magnesia and spinel 1-1.2. Magnesia Magnesium oxide (MgO, magnesia) occurs naturally as the mineral periclase; a metamorphic mineral formed by the breakdown of dolomite, CaMg (CO
More informationSupplementary Information for the Paper Ref. B207765F. Fig. S1 shows the simultaneous TG / DTA curves of the gel-carbonate precipitate.
Supplementary Information for the Paper Ref. B207765F Photoluminescence of Sr 2-x Ln x CeO 4+x/2 (Ln = Eu, Sm or Yb) prepared by a wet chemical method. Abanti Nag and T. R. Narayanan Kutty* Thermoanalytical
More informationElectrical Properties of Polymers, Ceramics, Dielectrics, and Amorphous Materials. Dae Yong JEONG Inha University
Electrical Properties of Polymers, Ceramics, Dielectrics, and Amorphous Materials Dae Yong JEONG Inha University Review & Introduction We learned about the electronic transfer in Metal and Semiconductor.
More informationPhysical Ceramics. Principles for Ceramic Science and Engineering. Yet-Ming Chiang Massachusetts Institute of Technology Cambridge, Massachusetts
Physical Ceramics Principles for Ceramic Science and Engineering Yet-Ming Chiang Massachusetts Institute of Technology Cambridge, Massachusetts Dunbar P. Birnie, III University of Arizona Tucson, Arizona
More informationSupplementary Information for A Shortcut to Garnet-type Fast Li-Ion Conductors for All Solid State Batteries
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A. This journal is The Royal Society of Chemistry 2015 Supplementary Information for A Shortcut to Garnet-type Fast Li-Ion Conductors
More informationCharacterization of Nanoscale Electrolytes for Solid Oxide Fuel Cell Membranes
Characterization of Nanoscale Electrolytes for Solid Oxide Fuel Cell Membranes Cynthia N. Ginestra 1 Michael Shandalov 1 Ann F. Marshall 1 Changhyun Ko 2 Shriram Ramanathan 2 Paul C. McIntyre 1 1 Department
More informationPassivation and Activation of SOFC Nanostructured Cathodes. Risoe National Laboratory, Technical University of Denmark, Roskilde 4000, Denmark
1243 10.1149/1.2729225, The Electrochemical Society Passivation and Activation of SOFC Nanostructured Cathodes W. G. Wang a,b, J. J. Bentzen a, S. H. Jensen a, N. Bonanos a, P. V. Hendriksen a, M. Mogensen
More informationDevelopment of Intermediate-Temperature Solid Oxide Fuel Cells for Direct Utilization of Hydrocarbon Fuels
University of Pennsylvania ScholarlyCommons Departmental Papers (CBE) Department of Chemical & Biomolecular Engineering November 2004 Development of Intermediate-Temperature Solid Oxide Fuel Cells for
More informationAmbient Temperature Aqueous Synthesis of Ultrasmall Copper Doped Ceria. Nanocrystals for the Water Gas Shift and Carbon Monoxide Oxidation Reactions
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A. This journal is The Royal Society of Chemistry 2017 Ambient Temperature Aqueous Synthesis of Ultrasmall Copper Doped Ceria
More informationChromium impact on Strontium and Manganese-free cathode materials
Chromium impact on Strontium and Manganese-free cathode materials M.K. Stodolny a B.A. Boukamp b D.H.A. Blank b G. Rietveld a F.P.F. van Berkel a a University of Twente, Department of Science and Technology
More informationChapter 2. Ans: e (<100nm size materials are called nanomaterials)
Chapter 2 1. Materials science and engineering include (s) the study of: (a) metals (b) polymers (c) ceramics (d) composites (e) nanomaterials (f) all of the above Ans: f 2. Which one of the following
More informationPreparation of rare earth oxide doped alumina ceramics, their hardness and fracture toughness determinations
Indian Journal of Engineering & Materials Sciences Vol. 13, October 2006, pp. 443-450 Preparation of rare earth oxide doped alumina ceramics, their hardness and fracture toughness determinations Kuntal
More information