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      https://www.ias.ac.in/article/fulltext/boms/023/02/0087-0090

    • Keywords

       

      Polycrystalline ferrite; rare-earth; Seebeck coefficient; electron hopping; Fermi energy

    • Abstract

       

      Polycrystalline ferrites, ZnxMg1−xFe2−yNdyO4 (x = 0.00, 0.20, 0.40, 0.60, 0.80 and 1.00;y = 0.00, 0.05 and 0.10) were prepared by standard ceramic method. X-ray diffraction study of these compositions revealed the formation of single phase spinels. Seebeck coefficient was obtained from thermo emf measurement by keeping constant temperature difference of 10 K across the pellet. The values of Seebeck coefficient were found to be negative showing majority charge carriers ofn-type, suggesting the mechanism of conduction to be predominantly by electron hopping. The substitution of Nd3+ ion, which perhaps resides at the B-site, resulting in a decrease in the Seebeck coefficient. This decrease was assigned to the decrease of population of Fe3+ ion at the B-site. The activation energies calculated both from mobility plots and from dc resistivity plots were found comparable. The Fermi energy,EF(0), which was estimated by intrapolation ofEF-T curves toT = 0 K, was found less than the activation energy. This difference was attributed to electron hopping energy.

    • Author Affiliations

       

      B P Ladgaonkar1 P N Vasambekar1 A S Vaingankar1

      1. Department of Electronics, Shivaji University, Kolhapur - 416 004, India
    • Dates

       
  • Bulletin of Materials Science | News

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