Large As sublattice distortion in sphalerite ZnSnAs2 thin films revealed by x-ray fluorescence holography

Abstract

The structure of a ZnSnAs2 thin film epitaxially grown on an InP substrate was evaluated using x-ray fluorescence holography. The reconstructed three-dimensional atomic images clearly show that the crystal structure of the ZnSnAs2 thin film is mainly of the sphalerite type, in contrast to the bulk form. A large disordering of the As layers is observed, whereas the positions of the Zn/Sn atoms are relatively stable. The analysis of the data indicates that the As layers serve as a buffer and relax the strain caused by the random occupation of Zn and Sn atoms. These results provide further understanding and a means of controlling the growth of Mn-doped ZnSnAs2, a high-Tc diluted magnetic semiconductor.

X‐Ray Fluorescence Holography Analysis of Local Structure in CuInSe2 and CuGaSe2

“…In the ternary II‐IV‐V 2 semiconductors, XFH experiments have been performed on an epitaxial ZnSnAs 2 films grown on an InP substrate . The result shows that the local structure of ZnSnAs 2 layer has been explained by a sphalerite structure rather than a chalcopyrite structure …”

Local Structure of FeSe0.4Te0.6 by Low‐Temperature X‐Ray Fluorescence Holography

“…This means that no specific model of the atomic structure is necessary beforehand for the analysis of the XFH data, in contrast to e.g., XAFS, where a good model is usually required to analyze the experimental data. XFH can visualize the local structure in principle up to several nm (e.g., in Hayashi et al), thus representing a link between information derived from XAFS (usually only suitable to study nearest or next‐nearest neighbors) and XRD results (which only probes the average structure). In this work, we will present XFH measurements for the FeSe 0.4 Te 0.6 superconductor, which has a T C of 13.5 K .…”

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

“…The advantages of the XFH technique are listed as follows: –3D atomic images can be obtained with no special models. –Local atomic structures can be evaluated around a specific element up to more than 15 neighboring atoms (see Figure d–f of Hayashi et al for a GaAs crystal). –No special limitations for impurities or low dimensional samples such as thin films. –Spatial fluctuations can be determined for each neighboring atoms. –Single phases are not necessary for the sample. …”