TITLE

Interionic interactions and fast-ion conduction in CaF2

AUTHOR(S)
Wilson, Nicholas T.; Wilson, Mark; Madden, Paul A.; Pyper, Nicholas C.
PUB. DATE
December 1996
SOURCE
Journal of Chemical Physics;12/22/1996, Vol. 105 Issue 24, p11209
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Simulations of the superionic conductor CaF[SUB2] have been undertaken, with a model for the interionic interactions derived directly from electronic structure calculations. The model includes such many-body effects as polarization and the adaptation of the size of the anion to its instantaneous environment ("compression"). Physical properties of CaF[SUB2] accurately reproduced include the phonon frequencies, the fluorite → α-PbCl[SUB2]-structure phase transition and the solid-state diffusion. Analysis shows that the compression effect is much less important for fluorides than oxides but, nevertheless, significantly affects the phase transition pressure. Polarization effects, particularly of the cations, play a crucial role in allowing the anion diffusion, and the importance of a short-range contribution to the cation polarization is highlighted. These findings are contrasted with previous work using empirically parametrized shell and pair potentials, which suggest that other interactions play the dominant role.
ACCESSION #
9815238

 

Related Articles

  • Structural mechanisms of superionic conductivity in M RF single crystals. Sorokin, N.; Golubev, A.; Sobolev, B. // Crystallography Reports;Mar2014, Vol. 59 Issue 2, p238 

    The relationship between the superionic transport in fluorite phases M RF ( M = Ca, Sr, or Ba; R are rare earth elements) and their defect structure has been analyzed. The superionic conductivity of M RF crystals is provided by the high concentration of charge carriers. However, the carrier...

  • Electronic structure of lead (II) fluoride and lead (II) chloride crystals. Murin, I. V.; Petrov, A. V.; Tupitsyn, I. I.; Évarestov, R. A. // Physics of the Solid State;Feb98, Vol. 40 Issue 2, p211 

    The method of complete neglect of differential overlap was used to calculate the electronic structure of α PbF[sub 2], Β PbF[sub 2], and PbCl[sub 2] crystals which form the basic matrices for the synthesis of new superionic conductors. It was shown that the electronic subsystem is fairly...

  • Mechanochemical synthesis and electrical properties of GdHfZrO solid electrolytes for their use in SOFC's. Cepeda-Sánchez, N.; Fuentes, A.; López-Cota, F.; Rodríguez-Reyes, M.; Díaz-Guillén, J. // Journal of Applied Electrochemistry;Nov2015, Vol. 45 Issue 11, p1231 

    Lanthanides hafnates LnHfO (Ln = lanthanides) are known by their interesting electrical properties; many of them are good oxygen ion conductors at high temperatures and can be used as solid electrolytes in solid oxide fuel cells. Properties of these materials are significantly affected by the...

  • First-principle calculation of core level binding energies of LixPOyNz solid electrolyte. Guille, Émilie; Vallverdu, Germain; Baraille, Isabelle // Journal of Chemical Physics;12/282014, Vol. 141 Issue 24, p1 

    We present first-principle calculations of core-level binding energies for the study of insulating, bulk phase, compounds, based on the Slater-Janak transition state model. Those calculations were performed in order to find a reliable model of the amorphous LixPOyNz solid electrolyte which is...

  • Temperature dependence of the ionic conductivity in Li[sub 3x]La[sub 2/3-x]TiO[sub 3]: Arrhenius versus non-Arrhenius. Rivera, A.; Santamarıa, J.; León, C.; Blochowicz, T.; Gainaru, C.; Rössler, E. A. // Applied Physics Letters;4/14/2003, Vol. 82 Issue 15, p2425 

    We report on the temperature dependence of the ionic conductivity at low temperatures in the crystalline lithium ionic conductor Li[sub 0.18]La[sub 0].61]TiO[sub 3]. Time domain measurements of the electric modulus have been performed to investigate ion dynamics in the frequency range 10[sup...

  • The influence of elastic stress fields on ionic transport through a 〈superionic crystal〉– heterojunction. Bredikhin, S. I.; Bogatyrenko, M. V. // Physics of the Solid State;Oct99, Vol. 41 Issue 10, p1620 

    The appearance of a current in an external circuit has been observed upon elastic deformation of a local region of the superionic crystal RbAg[sub 4]I[sub 5]. The dependence of the magnitude and sign of the deformation current on the region of application of the local load on the sample is...

  • Precipitation of mobile copper from Cu[sub 2-x]Se samples under impact loading. Korzhuev, M. A. // Technical Physics Letters;Mar97, Vol. 23 Issue 3, p196 

    It has been found that the rate of copper precipitation from samples of the superionic conductor copper selenide, Cu[sub 2-x]Se, exposed to impact loading is substantially higher than that under static pressure. This effect is attributed to the action of excess pressures and temperatures at...

  • Effect of free electrons on growth of ‘‘cancers’’ in mixed electronic–ionic conductors. Korzhuev, M. A. // JETP Letters;7/25/96, Vol. 64 Issue 2, p105 

    The reasons for the anomalously rapid (for solids) growth of ‘‘cancers’’ (filamentary crystals, hills, pores, and other formations) on the surface of samples of superionic conductors with mixed electronic–ionic conductivity (of the type Cu2-xSe and Ag2Te) are...

  • Structure of Conduction Channels in Superionic Conductors: Crystallochemical Modeling. Polyakov, V. I. // Crystallography Reports;May2001, Vol. 46 Issue 3, p435 

    The experimental and theoretical studies of the structure of conduction channels of superionic conductors are analyzed. A crystallochemical method of modeling the conduction channels is proposed in which they are treated as sets of polyhedron Voronoi-Dirichlet sections outside of impenetrable...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics