4.7 Article

The Sr2.4Dy0.6Co2O7-δ Ruddlesden-Popper Phase: Structural, thermoelectric, and magnetic properties

期刊

CERAMICS INTERNATIONAL
卷 47, 期 7, 页码 9068-9074

出版社

ELSEVIER SCI LTD
DOI: 10.1016/j.ceramint.2020.12.030

关键词

Rare-earth substituted cobalt oxides; Ruddlesden-Popper phase; Thermoelectric oxide materials; Magnetic properties

资金

  1. Russian Foundation for Basic Research [19-03-00017]
  2. Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences [AAAA-A17117021310222-4]

向作者/读者索取更多资源

A new anion-deficient Sr2.4Dy0.6Co2O7-delta perovskite phase has been synthesized and characterized, showing specific crystal parameters and oxygen vacancy distribution. The compound exhibits stability under various atmospheres and reversible oxygen absorption/release at high temperatures. Additionally, magnetic properties and electrical conductivity changes have been investigated in detail.
A new anion-deficient Sr2.4Dy0.6Co2O7-delta (delta = 0.33-1.1) perovskite phase with a structure of the A(3)B(2)O(7) Raddlesden-Popper homologous series has been obtained by the solid-state synthesis in the reducing/oxidizing atmosphere and its structural characterization has been performed by the Rietveld refinement of the X-ray powder diffraction data. It has been stablished that the Sr2.4Dy0.6Co2O7-delta compound (sp. gr. I4/mmm) has parameters of a = b = 3.8526(1) and c = 19.9431(7) angstrom, in the reduced form (delta = 1.1) and a = b = 3.8086(1) and c = 19.9190(6) angstrom, in the oxidized form (delta approximate to 0.33) and oxygen vacancies occupy mainly the sites linking CoO5 polyhedra inside two perovskite layers. It has been established using differential scanning calorimetry and thermogravimetry that, at T < 530 K, the synthesized phase is stable against the inert and oxidizing atmosphere; at higher temperatures, the Sr2.4Dy0.6Co2O7-delta compound can reversibly absorb/release oxygen. The magnetic properties of the Sr2.4Dy0.6Co2O6.09 compound have been investigated in the temperature range of 10-400 K and described in terms of the formation of dimers, in which the Co3+-Co3+ and Co2+-Co2+ ion pairs antiferromagnetically interact and are in the nonmagnetic ground state. The electrical conductivity and the Seebeck coefficient have been measured in air in the temperature range from 300 to 800 K. An observed sharp decrease in the Seebeck coefficient of the Sr2.4Dy0.6Co2O7-delta compound and the change in its sign near 700 K have been attributed to the transition of cobalt ions to the Co3+ state and the charge disproportionation of Co3+ ions to Co2+ and Co4+ ones.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据