Relationship between oxygen desorption and the reduction features of Mn and Fe in perovskite-type SrFe1−xMnxO3−δ

• Published in: Journal of solid state chemistry Vol. 283; p. 121152
• Main Authors: Fujishiro, Fumito, Oshima, Natsumi, Kamioka, Nanako, Sakuragi, Tokio, Oishi, Masatsugu
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.03.2020
• Subjects: Iron; Manganese; Oxygen desorption; Perovskite; Reduction; Thermogravimetry; Perovskite; Oxygen desorption; Reduction; Iron; Thermogravimetry; Manganese
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2019.121152

Perovskite-type (ABO3) SrFe1−xMnxO3−δ specimens (0.1 ​≤ ​x ​≤ ​0.6) were prepared via the Pechini method. The Mn and Fe valences were determined by means of X-ray absorption fine structure spectroscopy and iodometry, and the average B valences and oxygen contents (3−δ) were calculated from the obtained valences. In perovskite SrFe1−xMnxO3−δ specimens, it was found that oxide ion vacancies existed on several octahedra. Thermogravimetry showed that the degree of oxygen desorption increased upon increasing the temperature but decreased at higher Mn contents, thereby indicating that Mn ions were not reduced in the obtained cubic perovskite phase. It was therefore considered that Fe ions were more easily reduced, and that the crystal structure was stable during oxygen desorption, thereby suppressing the reduction of Mn ions in the B-site mixed perovskite-type SrFe1−xMnxO3−δ. In the cubic perovskite-type SrFe1−xMnxO3−δ (0.1 ​≤ ​x ​≤ ​0.6), the oxygen desorption during heating under air depends on reduction of the Fe ions, and the reduction of Mn ions is suppressed. [Display omitted] •Perovskite-type SrFe1−xMnxO3−δ specimens were prepared (0.1 ​≤ ​x ​≤ ​0.6).•Mn ions were not reduced in the obtained cubic perovskite phase.•Fe ions were more easily reduced in the perovskite structure.