Thermoelectric power studies of Sn/Nb substituted Mn-Zn ferrites

Thermoelectric power studies of polycrystalline materials of Sn/Nb substitu ted Mn-Zn ferrites have been carried out. The Seebeck coefficient, carrier concentration and drift mobility were evaluated. The Seebeck coefficient in creases up to 420 K and 400 K for Nb and Sn substituted ferrites respective ly. All the ferrites exhibited n-type conduction over the range of temperat ure studied. At high temperatures, a non-degenerate type of semiconductor b ehaviour has been observed. The conduction of these materials is explained by hopping of electrons from Fe2+ to Fe3+, in addition to the existence of narrow bands and localized levels. The variation of drift mobility is expla ined by wavy bands [1, 2]. (C) 1999 Kluwer Academic Publishers.