A new iron pnictide oxide (Fe2As2)(Ca-5(Mg, Ti)(4)O-y) and a new phase in the Fe-As-Ca-Mg-Ti-O system

作者：Ogino Hiraku^*; Shimizu Yasuaki; Kawaguchi Naoto; Kishio Kohji; Shimoyama Jun ichi; Tohei Tetsuya; Ikuhara Yuichi

来源：Superconductor Science and Technology, 2011, 24(8): 085020.

DOI：10.1088/0953-2048/24/8/085020

A new layered iron arsenide oxide (Fe2As2)(Ca-5(Mg, Ti)(4)O-y) and its structural derivative were found in the Fe-As-Ca-Mg-Ti-O system. The crystal structure of (Fe2As2)(Ca-5(Mg, Ti)(4)O-y) is identical to that of(Fe2As2)(Ca-5(Sc, Ti)(4)O-y), which was reported in our previous study. The lattice constants of this compound are a = 3.86(4) angstrom and c = 41.05(2) angstrom. In addition, another phase with a thicker blocking layer was found. The structure of the compound was tentatively assigned through scanning transmission electron microscope observation as (Fe2As2)(Ca-8(Mg, Ti)(6)O-y) with sextuple perovskite-type sheets divided by a rock salt layer. The interlayer Fe-Fe distance of this compound is similar to 30 angstrom. These compounds exhibited bulk superconductivity, as found from magnetization and resistivity measurements.

• 出版日期2011-8