Advertisement

Growth and Characterization of Some New Superionic Phosphates

  • K. Byrappa

Abstract

The search for new sodium superionic conductors is becoming very popular with the development of NASICON whose ionic conductivity is equivalent to that of Na β — alumina. NASICON poses a challenge to Materials Scientists in understanding its structure and conduction mechanism due to the lack of single crystals, non-stoichiometry in the composition, zirconium deficiency, etc. It is a solid solution between NaZr2P3O12– Na4Zr2Si3O12. Then came several new triorthophosphates, which became popular as NASICON analogues with their simple structures and stoichiometric composition. However, all the compounds whether NASICON or NASICON analogues always had only the triorthophosphate end members and their structures were directly related to Na3Sc2P3O12. Here, the author reports the ionic conductivity in condensed phosphates, particularly pyrophosphates, for the first time, showing high ionic conductivity. These pyrophosphates have been grown by hydrothermal method. The author has reported some of these pyrophosphates in brief as the perspective superionics very recently. These condensed phosphates are much easier to obtain in the form of single crystals with stoichiometric composition. The structures vary from the regular NASICON type. Although, cations form the usual octahedra, Na+ atoms lying in the cavities, but the framework linking differs. The conductivity is attributed to the diffusion of Na+ through a network of tunnels in a rigid structure made up of pyrophosphate anions sharing corners with ZrO6/MO6 octahedra. This has opened a new chapter in the search for new Na+ superionic conductors even among the condensed phosphates and silicates. The pyrophosphates considered here have a wide range of cationic groups. The author has discussed in the present work, the growth, structure and impedence spectroscopy of these new pyrophosphate superioncs.

Keywords

Solid State Ionic High Ionic Conductivity Superionic Conductor Trivalent Metal Hydrothermal Growth 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    S.Chandra, Superionic Solids, Elsevier Science Publishers, p. 17 (1981).Google Scholar
  2. 2.
    M.Faraday, Experimental Researches in Electricity, Taylor and Francis, London, p. 120 (1839).Google Scholar
  3. 3.
    E.Warburg,“Sodium ions migration through glass,” Wiedemann Ann, Phys., 21 622–24 (1884).Google Scholar
  4. 4.
    W.Nernst, “Ionic Conductivity in Mixed Oxides,” Z.Electrochem., 641– 44 (1899).Google Scholar
  5. 5.
    C.Tubandt and E.Lawrence, “Silver Conductivity in Alpha-AgI,” Z.Physik Chem., 87513– 43 (1914).Google Scholar
  6. 6.
    J.B.Goodenough, H.Y.-P.Hong and J.A.Kafalas, “Fast Na+ Ion Transport in Skeleton Structures,” Mat. Res. Bull., 11203– 20 (1976).CrossRefGoogle Scholar
  7. 7.
    K.Byrappa and G.S.Gopalakrishna, “A Critical Survey on the Study of Alkaline Rare Earth Phosphate and NASICOK Systems with a Special Reference to the Hydro- thermal Method,” Prog. Crystal Growth Charact., 789– 105 (1985).CrossRefGoogle Scholar
  8. 8.
    H.Y.-P.Hong, “Structure of Na3Zr2Psi2O12” Mat. Hes. Bull., 11 173–76 (1976).Google Scholar
  9. 9.
    V.A.Efremov and V.B.Kalinin,“Determination of Crystal Structure of Na3Sc2(PO4)3,” Kristallografia 23 703–708 (1978).Google Scholar
  10. 10.
    J.P.Boilot, Q.Collin and Ph.Colomban, “NASICON and Related Compounds: A Review,” Ed. T.W.Wheat, Progress in Solid Electrolytes, Energy, Mines, Resources, Ottawa, 91–122 (1983).Google Scholar
  11. 11.
    J.B.Goodenough, “Fast Ionic Conductors,” International School on Advanced Materials,of Erice, Italy (1980).Google Scholar
  12. 12.
    K.Byrappa, Ph.D. Thesis, Moscow State University (l98l).Google Scholar
  13. 13.
    L.O.Atomyan, O.S.Filipenko, V.I.Panomarev, L.S.Leonova and E.A.Ukshe, “Crystal Structure and Ionic Conductivity of Solid Electrolytes M5RESi4O12 where M = Na, Ag, RE = Sm → Lu,” Solid State Ionics 14137– 42 (1984).CrossRefGoogle Scholar
  14. 14.
    A.Feltz and S.Barth, “Preparation and Conductivity Behaviour of Na3MMZr(PO4)3 MN = Mn, Mg, Znz” Solid State Ionics 9& 10817– 22 (1983).CrossRefGoogle Scholar
  15. 15.
    K.Byrappa, G.S.Gopalakrishna, A.B.Kulkarai and Y.Yenkatachalapathy, “Synthesis and Characterization of Na2(R,Co)Zr(PO4)3 Crystals,” J. Less Common Metals 110441– 44 (1985).CrossRefGoogle Scholar
  16. 16.
    M. de la Rochere, F.d’Yuoire, G.Collin, R.Come’s and J.P.Boilot, “NASICON type Materials– Na3M2(PO4)3 (M= Sc,Cr,Fe): Na+ - Na+ Correlations and Phase Transitions,” Solid State Ionics 9& 10825– 28 (1983).Google Scholar
  17. 17.
    F.d’Yvoire, K.Pintard-Screpel, E.Bretcy and M.de la Rochere, “Phase Transition and Ionic Conduction in 3d Skeleton Phosphates A3M2(PO4)3: A= Li,Na,Ag,K; M = Cr,Fe,” Solid State Ionics 9& 10851– 58 (1983).CrossRefGoogle Scholar
  18. 18.
    K.Byrappa, G.S.Gopalakrishna and S.Gali, “Synthesis and Characterization of a New Superionic Polyphosphate,” Indian J. Fhys., 63A321– 25 (1989).Google Scholar
  19. 19.
    K.Byrappa, G.S.Gopalakrishna and S.Gali, “Synthesis and Characterization of a New Superionic Polyphosphate,” Indian J. Fhys., 63A321– 25 (1989).Google Scholar
  20. 20.
    K.Byrappa, G.S.Gopalakrishna and S.Gali, “Synthesis and Characterization of a New Superionic Polyphosphate,” Indian J. Fhys., 63A321– 25 (1989).Google Scholar
  21. 21.
    A.Clearfield, S.Oubramanian, W.Wong and P.Serus, “The Use of Hydrothermal Procedures to Synthesize NASICON and Some Comments on the Stoichiometry of NASICON Phases,” Solid State Ionics 9& 10895– 902 (1983).CrossRefGoogle Scholar
  22. 22.
    F.Genet and M.Barj, “Hydrothermal Synthesis and Recrystallization of Compounds belonging to the NASICON Family: Synthesis and Crystallization of Sodium Zirconium Silicon Oxide– Na4Zr2Si3O12,” solid State Ionics 9& 10891–93 (1983).Google Scholar
  23. 23.
    K.Carron, M. Morse and K.Murata, “Relation of Ionic Radius to Structure of Rare Earth Phosphates, Arsenates and Vanadates,” Amer. Min., 43985– 86 (1958).Google Scholar
  24. 24.
    J.N.Anthony, “Hydrothermal Synthesis of Honazite,” Amer. Min., 42904– 6 (1957).Google Scholar
  25. 25.
    H.M.Kurbamov, V.Yu.Kara-Ushnov and -B.C.Halikov, “Orthophosphates of Rare Earth Elements,” Danish Publishers, Dushanbe, p. 128 (1981) (in Russian)Google Scholar
  26. 26.
    V.K.Jahn and Kordes, “Hydrothermal Synthesis of Large Aluminium Phosphate Crystals,” Chem. Earth 7075– 78 (1953).Google Scholar
  27. 27.
    J.M.Stanley, “Hydrothermal Growth of A1PO4,” Ind. Eng. Chem., 461684– 89 (1954).CrossRefGoogle Scholar
  28. 28.
    M.Yoshimura, K.Fuji and S.Somiya, “Phase Equilibria in the System Nd2O3 - P2O5 - H2O at 500° C under 100 MPa and Synthesis of NdP5O14 Crystals,” Mater. Res. Bull., 16327– 31 (1981).CrossRefGoogle Scholar
  29. 29.
    L.Yonghua, M.Hinghai, Z.Qinglian, S.E.Endong, W.Mingyi, L.Shuzhen and W.Shixue, “Crystal Structure of Erbium Pentaphosphate,” Kexue Tongbao 27 1126–30 (1982) (in Chinese)Google Scholar
  30. 30.
    K.Byrappa and B.N.Litvin, “Hydrothermal Synthesis of Mixed Phosphates of Neodymium and Alkaline Metals (Me2O • Nd2O3 •4 P2O5),” Mater. Sci., 18703– 08 (1983).CrossRefGoogle Scholar
  31. 31.
    K.Byrappa, “A Possible Reasons for the Absence of Condensed Phosphates in Nature,” Phys. Chem. Minerals 1094– 95 (1983).CrossRefGoogle Scholar
  32. 32.
    P.R.Rudolf, M.A.Subramanian, and A.Clearfield, “The Crystal Structure of a non stoichiometric NASICON, ” M.ter. Res. Bull., 20643– 51 (1985).CrossRefGoogle Scholar
  33. 33.
    J.MHodge, M.D.Ingram and A.R.West, J. Electroanal. Chem., 74125– 29 (1976).CrossRefGoogle Scholar

Copyright information

© Elsevier Science Publishers Ltd. 1990

Authors and Affiliations

  • K. Byrappa
    • 1
  1. 1.The Mineralogical InstituteUniversity of MysoreManasagangotri MysoreIndia

Personalised recommendations