Influence of Nd3+ substitution on thermoelectric power of Zn-Mg ferrite system

• Published in: Bulletin of materials science Vol. 23; no. 2; pp. 87 - 90
• Main Authors: Ladgaonkar, B. P., Vasambekar, P. N., Vaingankar, A. S.
• Format: Journal Article
• Language: English
• Published: Bangalore Springer Nature B.V 01.04.2000
• Subjects: Activation energy; Current carriers; Ferrites; Hopping conduction; Seebeck effect; Substitutes
• ISSN: 0250-4707; 0973-7669
• DOI: 10.1007/BF02706547

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.