Small polaron and bipolaron transport in antimony oxide doped barium hexaferrites

Abstract

Direct current electrical resistivity measurements on specimens with composition BaO (6-x) Fe2O3, x Sb2O3 with x having values of 0.0, 0.025, 0.05, 0.1, and 0.3, respectively, were carried out in the temperature range of 120-300 K. Chemical analyses showed the presence of Sb3+ and Sb5+ ions as well as Fe2+ and Fe3+ ions in the doped specimens. The doped specimens were found to have reduced resistivities. The analysis of the data shows that the electrical conductivity in this system arises due to a combined contribution of both small polaron hopping between Fe2+ and Fe3+ sites and bipolaronic transport between Sb3+ and Sb5+ sites. © 2000 American Institute of Physics.