Stępień Joanna, Rybicki Damian, Sikora Marcin, Bukowski Zbigniew, Babij Michał, Gondek Łukasz, Kapusta Czesław, Strączek Tomasz, Goc Kamil, Oliveira De Souza Danilo
Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059, Kraków, Poland.
Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059, Kraków, Poland.
Sci Rep. 2023 Aug 12;13(1):13123. doi: 10.1038/s41598-023-40419-8.
Superconductivity in high-temperature superconductors such as cuprates or iron pnictides is typically achieved by hole or electron doping and it is of great interest to understand how doping affects their properties leading to superconductivity. To study it we conducted Fe and As K edge x-ray absorption spectroscopy measurements on several electron doped compounds from the 112 and 122 family of Eu-based iron pnictides. XANES and EXAFS results confirm that dopants are located at expected sites. For both families we found an electron charge redistribution between As and Fe occurring with doping. The changes it caused are stronger in the 112 family and they are bigger at As sites, which indicates that doped charges are predominantly localized on the dopant site. However, the results obtained do not provide clues why Ni doping in 122 family does not lead to occurrence of superconductivity.
在铜酸盐或铁基氮化物等高温超导体中，超导性通常通过空穴或电子掺杂来实现，了解掺杂如何影响其导致超导性的性质是非常有趣的。为了研究这一点，我们对基于铕的铁基氮化物112和122族的几种电子掺杂化合物进行了铁和砷K边X射线吸收光谱测量。XANES和EXAFS结果证实掺杂剂位于预期位置。对于这两个族，我们发现随着掺杂，砷和铁之间发生了电子电荷重新分布。它在112族中引起的变化更强，在砷位点处变化更大，这表明掺杂电荷主要定域在掺杂剂位点上。然而，所获得的结果并未提供关于为什么122族中的镍掺杂不会导致超导性出现的线索。
