Cation doping and oxygen diffusion in zirconia: a combined atomistic simulation and molecular dynamics study

Computer simulation techniques have been used to investigate the defect and transport properties of the zirconia (ZrO2) oxygen-ion conductor. First, a wide variety of low-valent metal ions are substituted into zirconia, and the energetics of solution investigated. Favourable dopants (on energetic grounds) have been calculated and include CaO, Y2O3 , Gd2O3 ,and Sc2O3 in agreement with observation. Dopant-vacancy clusters are also examined with the results revealing trends with dopant ion size and significant local atomic relaxation. These simulations are extended to encompass the topical area of Nb/Y co-doping in zirconia. Oxygen ion diffusion in yttria-stabilised zirconia is studied by application of molecular dynamics (MD) techniques; our results support models in which diffusion is mediated by oxygen vacancies, with calculated diffusion coefficients and activation energies in accord with tracer diffusion studies.

[1]  W Smith,et al.  DL_POLY_2.0: a general-purpose parallel molecular dynamics simulation package. , 1996, Journal of molecular graphics.

[2]  Y. Chiang,et al.  Solute Segregation and Grain‐Boundary Impedance in High‐Purity Stabilized Zirconia , 1996 .

[3]  M. Watanabe,et al.  Effects of ionic conductivities of zirconia electrolytes on polarization properties of platinum anodes in solid oxide fuel cells , 1995 .

[4]  Xin Guo,et al.  Roles of alumina in zirconia-based solid electrolyte , 1995 .

[5]  Hisashi Suzuki,et al.  Molecular Dynamics Study of Superlattice Superionic Conductor: Enhancement of Oxygen Ion Diffusion in YSZ , 1994 .

[6]  L. Gauckler,et al.  The relaxation dispersion of the ionic conductivity in cubic zirconias , 1994 .

[7]  E. Lachowski,et al.  Sintering of a plasma derived zirconia powder for solid oxide fuel cell electrolytes , 1994 .

[8]  I. Chen,et al.  Effect of Dopants on Zirconia Stabilization—An X‐ray Absorption Study: III, Charge‐Compensating Dopants , 1994 .

[9]  N. Minh.  Ceramic Fuel Cells , 1993 .

[10]  W. J. Weber,et al.  Research needs and opportunities in highly conducting electroceramics , 1993 .

[11]  F. Shimojo,et al.  Molecular Dynamics Studies of Yttria Stabilized Zirconia. II. Microscopic Mechanism of Oxygen Diffusion , 1992 .

[12]  F. Shimojo,et al.  Molecular dynamics studies of yttria stabilized zirconia. I: Structure and oxygen diffusion , 1992 .

[13]  Sukhvinder P.S. Badwal,et al.  Zirconia-based solid electrolytes: microstructure, stability and ionic conductivity , 1992 .

[14]  I. Chen,et al.  Cubic‐to‐Tetragonal (t') Transformation in Zirconia‐Containing Systems , 1992 .

[15]  B. Steele.  Oxygen ion conductors and their technological applications , 1992 .

[16]  I. Chen,et al.  X-ray Absorption Studies of Ceria with Trivalent Dopants , 1991 .

[17]  C. Catlow.  Atomistic mechanisms of ionic transport in fast-ion conductors , 1990 .

[18]  R. Baetzold,et al.  Atomistic simulation of ionic and electronic defects in YBa2Cu3O7. , 1988, Physical review. B, Condensed matter.

[19]  S. J. Rothman,et al.  EXAFS study of yttria stabilized cubic zirconia , 1988 .

[20]  T. Suemoto,et al.  Composition dependence of the ionic diffusion coefficients in yttria-stabilized zirconias , 1986 .

[21]  Saurin Majumdar,et al.  Stress and Fracture Behavior of Monolithic Fuel Cell Tapes , 1986 .

[22]  C. Catlow,et al.  EXAFS Study of Yttria‐Stabilized Zirconia , 1986 .

[23]  W. C. Mackrodt,et al.  Theoretical Estimates of Point Defect Energies in Cubic Zirconia , 1986 .

[24]  Masanori Kato,et al.  Electrical conductivity of yttria-stabilized zirconia single crystals , 1985 .

[25]  J. Baumard,et al.  Oxygen semipermeability and electronic conductivity in calcia-stabilized zirconia , 1982 .

[26]  J. Baumard,et al.  Study of the dc and ac electrical properties of an yttria-stabilized zirconia single crystal [ ( Z r O 2 ) 0.88 - ( Y 2 O 3 ) 0.12 ] , 1982 .

[27]  J. Cohen,et al.  X-ray diffraction study of Zr(Ca,Y)O2-x. I. The average structure , 1979 .

[28]  I. K. Naik,et al.  Electrical Conduction in Nb2 O 5 ‐ Doped Cerium Dioxide , 1979 .

[29]  T. Etsell,et al.  Electrical properties of solid oxide electrolytes , 1970 .

[30]  E. Subbarao,et al.  X‐Ray and Electrical Conductivity Study of the Fluorite Phase in the System ZrO2–CaO , 1963 .

[31]  F. Thévenot,et al.  Densification of Yttria‐Stabilized Zirconia Impedance Spectroscopy Analysis , 1997 .

[32]  M. Islam,et al.  Defect chemistry of LaBO3(B = Al, Mn or Co) perovskite-type oxides. Relevance to catalytic and transport behaviour , 1996 .

[33]  B. Steele.  Interfacial reactions associated with ceramic ion transport membranes , 1995 .

[34]  I. Chen,et al.  Effect of Dopants on Zirconia Stabilization—An X‐ray Absorption Study: I, Trivalent Dopants , 1994 .

[35]  S. Adler,et al.  Effects of long-range forces on oxygen transport in yttria-doped ceria: simulation and theory , 1993 .

[36]  J. Corish.  Calculated and experimental defect parameters for silver halides , 1989 .

[37]  E. Subbarao,et al.  Solid electrolytes with oxygen ion conduction , 1984 .