Nonstoichiometry and phase relationship of the SrFeO2.5SrFeO3 system at high temperature
1992; Elsevier BV; Volume: 99; Issue: 1 Linguagem: Inglês
10.1016/0022-4596(92)90301-b
ISSN1095-726X
AutoresJunichiro Mizusaki, M. Okayasu, Shigeru Yamauchi, Kazuo Fueki,
Tópico(s)Electronic and Structural Properties of Oxides
ResumoIn order to make clear the phase relationships and nonstoichiometry of the SrFeO2.5SrFeO3 system at elevated temperatures, measurements were made using high-temperature gravimetry and high-temperature powder X-ray diffraction (XRD) analysis under the controlled oxygen partial pressure of 1–10−5 atm at temperatures above 400°C. At 400–900°C, the system was found to consist of the SrFeO2.5+δ phase of the brownmillerite-type structure with small oxygen excess-type nonstoichiometry and the SrFeO3−δ phase of the cubic perovskite-type structure with large oxygen deficient-type nonstoichiometry. At temperatures above 900°C, the brownmillerite phase transformed to the perovskite-type and the system was composed of only the cubic perovskite-type phase.
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