@article{Ding2023, 
author = {Cui Ding and Yuanzhao Li and Shuaihua Ji and Ke He and Lili Wang and Qi-Kun Xue},
title = {Obtaining tetragonal FeAs layer and superconducting KxFe2As2 by molecular beam epitaxy},
year = {2023},
journal = {Nano Research},
volume = {16},
number = {2},
pages = {3040-3045},
keywords = {molecular beam epitaxy, topotactic reaction, tetragonal FeAs, KxFe2As2, interface enhanced superconductivity},
url = {https://www.sciopen.com/article/10.1007/s12274-022-4956-4},
doi = {10.1007/s12274-022-4956-4},
abstract = {Atomic characterization on tetragonal FeAs layer and engineering FeAs superlattices is highly desirable to get deep insight into the multi-band superconductivity in iron-pnictides. We fabricate the tetragonal FeAs layer by topotactic reaction of FeTe films with arsenic and then obtain KxFe2As2 upon potassium intercalation using molecular beam epitaxy. The in-situ low-temperature scanning tunneling microscopy/spectroscopy investigations demonstrate characteristic  2×2 reconstruction of the FeAs layer and stripe pattern of KxFe2As2, accompanied by the development of a superconducting-like gap. The ex-situ transport measurement with FeTe capping layers shows a superconducting transition with an onset temperature of 10 K. This work provides a promising way to characterize the FeAs layer directly and explore rich emergent physics with epitaxial superlattice design.}
}