A Study of Conductivity in the Sr(Fe_1−xTi_x)O_3−δ System

Abstract

The conductivity and conductivity‐temperature characteristics of the Sr(Fe1−xTixO3−δ system fired in air are studied by means of Mössbauer spectroscopy at room temperature and at 78 K. On the basis of quantitative analysis of the Fe4+ content in the solid solution, the concentrations of oxygen vacancies are calculated and the relationship between Fe4+ content and conductivity is found. It is also found that the turning points of conductivity and material constant B, as well as Fe4+ and the percentage of oxygen vacancies, occur at x=0.7 on the curve. When x=0.7, Fe3+ (II), which has never been reported before, disappears and the lattice parameters no longer vary with x. Besides Fe4+, Fe3+(II) is also a factor affecting the conductivity of this system.

Nonstoichiometry and Physical Properties of the SrSn1−Fe O3−System

“…The B site ions coordinate with six oxygen ions and the octahedra share corners with neighboring octahedra along the crystallographical x-, y-, and z-axes in ABO (1)(2)(3)(4)(5). The superexchange interaction between magnetic B ions through oxygen ions has an effect on magnetic and electrical properties.…”

Propane gas sensing with high-density SrTi0.6Fe0.4O(3−δ) ceramics evaluated by thermogravimetric analysis

“…14,17 The oxygen stoichiometry of the STF40 ceramics was estimated on the basis of previously published data. Zhou and Goodenough 17 give a value of 2.94(1) for the oxygen content (3 − δ), of the composition SrTi 0.6 Fe 0.4 O (3−δ) that was processed in air during sintering and a value of 2.92 is reported in a publication by Zhuang et al 18 On the assumption that the re-oxidized material at hand had attained a comparable oxidation state (3 − δ) = 2.93, the oxygen deficiency, δ, of the as-prepared material could be re-calculated from the measured weight gains and thus amounted to approximately 0.19.…”