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Journal of thermal analysis

, Volume 48, Issue 5, pp 1051–1067 | Cite as

Thermoanalytical investigations on the sol-gel synthesis of YBa2Cu3O72212;δ

  • G. V. Rama Rao
  • U. V. Varadaraju
  • S. Venkadesan
  • S. L. Mannan
Article

Abstract

The high temperature superconducting compound YBa2Cu3O72212;δ (Y-123) is synthesised by sol-gel process using various precursors viz., acetate, acetate-citrate, nitrate-citrate and acrylamide. The phase purity of the final product depends on the homogeneity of the gels which intern depends on the bonding of the metal ions in the gels. The samples prepared by acrylamide and nitrate-citrate gel routes yielded phase pure Y-123 compound with better superconducting properties. The mechanism of formation of Y-123 in all these four gel routes is established by characterising the gels and intermediate phases using TG, DTA and XRD techniques. Kinetic analysis is carried out on the mass loss data using the method proposed by Phadni's and Deshpande. Avrami-Erofeev nuclei growth in case of acrylamide, diffusion controlled process in nitrate-citrate and phase boundary reaction mechanisms in case of acetate-citrate gels are found to be responsible for the formation of Y-123 phase.

Keywords

reaction mechanisms sol-gel superconductors thermoanalytical techniques 

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Copyright information

© Akadémiai Kiadó 1997

Authors and Affiliations

  • G. V. Rama Rao
    • 1
  • U. V. Varadaraju
    • 1
    • 2
  • S. Venkadesan
    • 1
  • S. L. Mannan
    • 1
  1. 1.Materials Development DivisionIndira Gandhi Centre for Atomic ResearchKalpakkam
  2. 2.Materials Science Research CentreIndian Institute of TechnologyMadrasIndia

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