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arXiv · 1006.3769

A New Iron Pnictide Oxide (Fe2As2)(Ca5(Mg,Ti)4Oy) and a New Phase in Fe-As-Ca-Mg-Ti-O system

Hiraku Ogino·Yasuaki Shimizu·Naoto Kawaguchi·Kohji Kishio·Jun-ichi Shimoyama·Tetsuya Tohei·Yuichi Ikuhara
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Abstract

A new layered iron arsenide oxide (Fe2As2)(Ca5(Mg,Ti)4Oy) and its structural derivative were found in the Fe-As-Ca-Mg-Ti-O system. The crystal structure of (Fe2As2)(Ca5(Mg,Ti)4Oy) is identical to that of (Fe2As2)(Ca5(Sc,Ti)4Oy), which was reported in our previous study. The lattice constants of this compound are a = 3.86(4) A and c = 41.05(2) A. In addition, another phase with a thicker blocking layer was found. The structure of the compound and its derivative was tentatively assigned through STEM observation as (Fe2As2)(Ca8(Mg,Ti)6Oy) with sextuple perovskite-type sheets divided by a rock salt layer. The interlayer Fe-Fe distance of this compound is ~30 A. The compound and its derivative exhibited bulk superconductivity, as found from magnetization and resistivity measurements.

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Hiraku Ogino, Yasuaki Shimizu, Naoto Kawaguchi, Kohji Kishio, Jun-ichi Shimoyama, Tetsuya Tohei, Yuichi Ikuhara. 2010-06-18. A New Iron Pnictide Oxide (Fe2As2)(Ca5(Mg,Ti)4Oy) and a New Phase in Fe-As-Ca-Mg-Ti-O system. https://doi.org/10.1016/j.physc.2012.02.039

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