期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：37
页码：18165-18165
DOI：10.1073/pnas.1909668116
出版社：The National Academy of Sciences of the United States of America
摘要：Li et al. (1) report on superconductivity ( T c ∼73 K) that emerged in Ba2CuO4- y (Ba214) synthesized at extremely high pressures (∼18 GPa). They claim that one of the unique features of this compound is an exceptionally compressed local octahedron. I read this article with great interest. However, I am afraid they stretch things a bit. While they claim the crystal structure of the compound is of the K2NiF4 (coined as T) type, as is the case with (La, Ba)2CuO4, their X-ray powder diffraction data resemble more the Nd2CuO4 (coined as T′)-type structure (2): In the latter, no local octahedron exists.
