Degree of order and redox balance in B-site ordered double-perovskite oxides, Sr2MMoO6−δ (M=Mg, Mn, Fe, Co, Ni, Zn)

✍ Scribed by S. Vasala; M. Lehtimäki; Y.H. Huang; H. Yamauchi; J.B. Goodenough; M. Karppinen

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 430 KB
• Volume: 183
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2010.03.004

✦ Synopsis

We have investigated a series of double-perovskite oxides Sr 2 MMoO 6 À d (M ¼ Mg, Mn, Fe, Co, Ni, Zn) for redox stability, oxygen content and crystal structure. Phases with M ¼Co, Ni and Zn were found to be oxygen-stoichiometric and stable under oxidizing conditions, whereas those with M¼ Mn and Fe were oxygen-deficient and stable under reducing conditions. The M¼ Mg phase is stable both under reducing and oxidizing conditions, showing variable oxygen contents within 0.00 r dr0.04 depending on the annealing conditions. Structural data indicate somewhat depressed values for the degree of M/Mo cation order and also evidence of electron transfer from M II to Mo VI for M¼ Mn, Fe and Co.