Synthesis, crystal growth and structure, magnetic and electrical properties of Ba₄Ru₂FeO₁₀ and Ba₄Ru₂CoO₁₀

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• 作者：L. Shlyk ; R. Niewa ; ^{rainer.niewa@iac.uni-stuttgart.de}
• 关键词：Ruthenate ; Crystal structure ; Magnetism ; Electrical resistivity
• 刊名：Solid State Sciences
• 出版年：2013
• 出版时间：May, 2013
• 年：2013
• 卷：19
• 期：Complete
• 页码：58-62
• 全文大小：484 K

文摘

Crystals of Ba₄Ru₂FeO₁₀ and Ba₄Ru₂CoO₁₀ (Cmca, Z?=?4, Ba₄Ru₂FeO₁₀: a?=?5.7899(1)??, b?=?13.2898(3)??, c?=?13.0098(4)??, V?=?1001.06??³; Ba₄Ru₂CoO₁₀: a?=?5.7691(2)??, b?=?13.2061(3)??, c?=?12.9755(4)??, V?=?988.57??³) were obtained from binary oxides and BaCoO₃ at 1300?¡ãC. Both compounds crystallize isostructural to Ba₄Ru₃O₁₀ with different preference of the 3d metal at the two crystallographic sites of Ru in the parent compound. Ba₄Ru₂FeO₁₀ exhibits a spin-glass like transition at 25?K, while Ba₄Ru₂CoO₁₀ does not show any magnetic order down to 2?K. According to electrical resistivity measurements performed on single crystals both compounds are semiconductors. In contrast to the variable-range hopping of the transport mechanism of Co bearing material, the electrical resistivity of Ba₄Ru₂FeO₁₀ follows an activation law resulting in a band gap of approximately 0.98?eV.