X-ray Fluorescence Holographic Study on High-Temperature Superconductor FeSe_0.4Te_0.6

Abstract

To observe the difference of atomic heights between the Se and Te layers with respect to the Fe layer in FeSe

Applications of a L1‐Regularized Linear Regression to X‐Ray Fluorescence Holography Data of Functional Materials

“…Figure shows a schematic diagram of the XFH apparatus. The figure is taken from Ideguchi et al The sample is placed on a two‐axes table of a diffractometer. The measurement is usually performed in inverse mode by changing two axes, typically, the incident angle of 0° ≤ θ ≤ 75° in steps of 1.00° and the azimuthal angle of 0° ≤ ϕ ≤ 360° in steps of about 0.35°.…”

“…Schematic diagram of the XFH apparatus. Reproduced with permission . Copyright 2015, Walter de Gruyter Berlin/Boston.…”

“…Thus, it is important to investigate the local structure of FeSe x Te 1− x around the Fe atoms. The preliminary XFH result on FeSe 0.4 Te 0.6 was published elsewhere, but a new analysis using using a L 1 ‐regularized linear regression method is published in this volume …”

“…The XFH experiments on the functional materials introduced in this article were performed in collaboration with the coauthors of Hosokawa et al, Stellhorn et al, and Ideguchi et al The authors thank Professor Ichiro Akai and Professor Masato Okada for useful information on the sparse modeling. The XFH experiments were performed at BL6C of PF‐KEK (Nos.…”

“…In this article, we present the excellent feasibility of the XFH measurements and the new data analysis by reviewing their applications to some functional materials with complex crystal structures, such as a determination of impurity sites in a Mn‐doped Bi 2 Te 3 topological insulator, a spin‐state selective structure in Fe 65 Ni 35 Invar alloy, and a lattice distortion in Fe chalcogenide room‐temperature superconductor …”