Bulletin of Materials Science

, Volume 14, Issue 3, pp 561–565 | Cite as

The role of basal-plane oxygen atoms in determining the ferroelastic and microstructural properties of Y-Ba-Cu-O

  • V K Wadhawan
International Conference On Superconductivity—II


The basal-plane oxygen atoms in YBa2Cu3O7−x behave like a lattice gas, with very high diffusivity, especially for oxygen-deficient specimens. Implicit in this behaviour is the property that even a small amount of stress applied along theb-axis (b >a) can make these oxygen atoms hop from the (0,1/2,0) sites to the (1/2,0,0) sites. This is suggested as the primary mechanism responsible for the ferroelastic switching observed in this crystal. Since the material is an oxide of a mixed-valence element (Cu), the common occurrence of overall nonstoichiometry is only to be expected. Also, as discussed by Khachaturyan and others, except at very high temperature, the oxygen atoms and the vacancies will always have a tendency for ordering and/or precipitation into configurations which approach near-perfect stoichiometry locally. However, not all evidence for ordering is in conformity with the predictions of Khachaturyan’s concentration-wave model. The experimental data are examined critically. Further experiments to resolve the discrepancies are suggested.


Ferroelastics Y-Ba-Cu-O phase transitions ordering precipitation disorientations 


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  1. Abrikosov A A, Buzdin A I, Kulic M L and Kuptsov D A 1988Int. J. Mod. Phys. 1 1045Google Scholar
  2. Alario-Franco M A, Chaillout C, Capponi J J, Chenavas J and Marezio M 1988Physica C156 455Google Scholar
  3. Anderson J S 1973J. Chem. Soc. Dalton Trans. 1107Google Scholar
  4. Bartelt N C, Einstein T L and Wille L T 1989Phys. Rev. B40 10759Google Scholar
  5. Cannelli G, Cantelli R and Cordero F 1988Phys. Rev. B38 7200Google Scholar
  6. Deutscher G and Mueller K A 1987Phys. Rev. B37 5837Google Scholar
  7. Dimos D, Choudhury P, Mannhart J and LeGoues F K 1988Phys. Rev. Lett. 61 219CrossRefGoogle Scholar
  8. Farrell D Eet al 1987Phys. Rev. B36 4025Google Scholar
  9. Goodenough J B and Manthiram A 1988 inHigh temperature superconductors (eds) J Heiraset al (Singapore: World Scientific) pp. 18–27Google Scholar
  10. Khachaturyan A G 1983Theory of structural transformations in solids (New York: Wiley)Google Scholar
  11. Khachaturyan A G and Morris J W 1988Phys. Rev. Lett. 61 215CrossRefGoogle Scholar
  12. Liu J Z, Lan M D, Klavins P and Shelton R N 1989 (Preprint)Google Scholar
  13. Somayazulu M S, Rao S M D and Wadhawan V K 1989Mater. Res. Bull. 24 795CrossRefGoogle Scholar
  14. Van Tendeloo G, Zandbergen H W and Amelinckx S 1987Solid State Commun.63 603CrossRefGoogle Scholar
  15. Varea C and Robledo A 1988 inHigh temperature superconductors (eds) J Heiraset al (Singapore: World Scientific) pp. 145–153Google Scholar
  16. Wadhawan V K 1982Phase Transitions 3 3CrossRefGoogle Scholar
  17. Wadhawan V K 1988Phys. Rev. B38 8936Google Scholar
  18. Wadhawan V K 1989Ferroelectrics 97 171Google Scholar
  19. Wadhawan V K and Bhagwat K V 1989Phase Transitions 19 27CrossRefGoogle Scholar
  20. Werder D J, Chen C H, Cava R J and Batlogg B 1988Phys. Rev. B37 2317Google Scholar
  21. You H, Axe J D, Kan X B, Moss S C, Liu J Z and Lam D J 1988Phys. Rev. B37 2301Google Scholar

Copyright information

© Indian Academy of Sciences 1991

Authors and Affiliations

  • V K Wadhawan
    • 1
  1. 1.Neutron Physics DivisionBhabha Atomic Research Centre, Tombay, Bombay 400 085IndoreIndia

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