Fused Perovskite Tunnel Structures in Ba5Fe6+xS4+xO8 (0.44≤x≤0.55) with x-Dependent Two-Stage Magnetizations

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• 作者：Taylor Wright ; Dr. Yurii Prots and Dr. Martin Valldor
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：August 1, 2016
• 年：2016
• 卷：22
• 期：32
• 页码：11303-11309
• 全文大小：2930K
• ISSN：1521-3765

文摘

Ba<sub>5sub>Fe<sub>6+xsub>S<sub>4+xsub>O<sub>8sub> was synthesized through a solid-state reaction, and pure powders of nominal compositions x=0.44&ndash;0.55 were obtained after being rinsed with water. The crystal structures (P4/mmm, a=10.13, c=4.03 Å) and sample purities were investigated by powder synchrotron X-ray diffraction and were found to be composed of a tunnel lattice (Ba<sub>5sub>Fe<sub>6sub>S<sub>4sub>O<sub>8sub>), built from fused perovskite units and the tunnel filling (Fe<sub>xsub>S<sub>xsub>). The variable composition, that is, the tunnel filling (x), causes partially occupied sites as well as crystallographic split positions. Ba<sub>5sub>Fe<sub>6+xsub>S<sub>4+xsub>O<sub>8sub> (x=0.525) is semiconducting and all investigated compositions exhibit magnetic ground states that could be described as either semi-spin-glass-like (x>0.5) or canted antiferromagnetic (x<0.5). The spin-glass in x=0.525 exhibits magnetic relaxations that are affected by ageing.