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Journal of Materials Science

, Volume 17, Issue 11, pp 3317–3326 | Cite as

Electrical transport in heavy rare-earth iron garnets

  • H. B. Lal
  • B. K. Verma
  • Vijayee Ram Yadav
Papers

Abstract

The measurements of electrical conductivity (σ) in the temperature range 450 to 1250 K and thermoelectric power (S) in the temperature range 600 to 1200 K of sintered pressed pellets of rare-earth iron garnets (REIG) with a general chemical formula RE3Fe5O12 (where RE=Y, Gd, Dy, Ho, Er and Yb) are reported. Values corresponding to the crystalline state have been evaluated employing pore fraction correction. It is observed that plots of log σT againstT−1 are linear with breaks in the slopes of temperatureT1 (lying between 560 and 578 K) andT2 (~ 1000 K). However, plots ofS againstT−1 are linear over the entire temperature range. The results have been discussed using the usual electrical transport theories and it has been concluded that electrical conduction in these solids up to a temperature of 1250 K is extrinsic in which holes localized on Fe3+ sites (Fe4+ centres created by native defects) conduct via a thermally activated hopping mechanism. Mobility activation energy, mobility and the number of such centres in each garnet are also evaluated.

Keywords

Iron Polymer Activation Energy Electrical Conduction General Chemical 
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.

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Copyright information

© Chapman and Hall Ltd. 1982

Authors and Affiliations

  • H. B. Lal
    • 1
  • B. K. Verma
    • 1
  • Vijayee Ram Yadav
    • 1
  1. 1.Department of PhysicsUniversity of GorakhpurGorakhpurIndia

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