Assessment of the optimum degree of Sr₃Fe₂MoO₉ electron-doping through oxygen removal: An X-ray powder diffraction and ⁵⁷Fe Mössbauer spectroscopy study

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• 作者：Carlos A. Ló ; pez ; Marí ; a del C. Viola ; José ; C. Pedregosa ; Roberto C. Mercader
• 关键词：A. Inorganic compounds ; A. Magnetic materials ; B. Chemical synthesis ; C. X-ray diffraction ; C. M&#xf6 ; ssbauer spectroscopy
• 刊名：Materials Research Bulletin
• 出版年：2010
• 出版时间：October 2010
• 年：2010
• 卷：45
• 期：10
• 页码：1520-1526
• 全文大小：465 K

文摘

We describe the preparation and structural characterization by X-ray powder diffraction (XRPD) and Mössbauer spectroscopy of three electron-doped perovskites Sr₃Fe₂MoO_9−δ with Fe/Mo = 2 obtained from Sr₃Fe₂MoO₉. The compounds were synthesized by topotactic reduction with H₂/N₂ (5/95) at 600, 700 and 800 °C. Above 800 °C the Fe/Mo ratio changes from Fe/Mo = 2–1 c; Fe/Mo c; 2. The structural refinements of the XRPD data for the reduced perovskites were carried out by the Rietveld profile analysis method. The crystal structure of these phases is cubic, space group , with cationic disorder at the two different B sites that can be populated in variable proportions by the Fe atoms. The Mössbauer spectra allowed determining the evolution of the different species formed after the treatments at different temperatures and confirm that Fe ions in the samples reduced at 600, 700 and 800 °C are only in the high-spin Fe³⁺ electronic state.