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    • Keywords


      Dielectric properties; relaxor; impedance and modulus spectroscopy

    • Abstract


      Valence compensated perovskite system Sr1 −xLaxTi1 −xCoxO3 shows dielectric relaxor behaviour with very high value of dielectric constant in the composition range 0·20 <x < 0·40. In this paper the effect of composition on microstructure and the resulting electrical behaviour is reported. The compositions withx = 0·25, 0·30, 0·33, 0·35 and 0·37 have been synthesized by solid state ceramic method and dielectric measurements were made in the temperature range of 300–500 K and frequency range of 100 Hz to 1 MHz. Grain boundaries played an important role in their dielectric behaviour. Complex plane impedance and modulus techniques were used to separate out the contributions of grain and grain-boundaries to the resulting dielectric behaviour. It was observed that the bulk resistivity as well as the grain boundaries resistance decreased with increasingx. Furthermore, impedance analysis demonstrated that extremely high value of dielectric constant observed in these materials was due to barrier layers formation at grain-grain-boundaries interfaces.

    • Author Affiliations


      Shail Upadhyay1 Devendra Kumar1 2 O M Parkash1

      1. School of Materials Science and Technology, Banaras Hindu University, Varanasi - 221 005, India
      2. Department of Ceramic Engineering, Institute of Technology, Banaras Hindu University, Varanasi - 221 005, India
    • Dates

  • Bulletin of Materials Science | News

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