Li YaJun, Hashimoto Yusuke, Kataoka Noriyuki, Sun Zexu, Kawamura Sota, Tomita Hiroto, Setoguchi Taro, Takeuchi Soichiro, Koga Shunjo, Yamagami Kohei, Kotani Yoshinori, Demura Satoshi, Noguchi Kanako, Sakata Hideaki, Matsushita Tomohiro, Wakita Takanori, Muraoka Yuji, Yokoya Takayoshi
Engineering Research Center of Integrated Circuit Packaging and Testing, Ministry of Education, Tianshui Normal University, Tianshui, 741001, Gansu, China.
Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
Sci Rep. 2025 Mar 11;15(1):8366. doi: 10.1038/s41598-025-86233-2.
Pb-substituted La(O, F)BiS (Pb-LaOFBiS) exhibits improved superconducting properties and a resistivity anomaly around 100 K that is attributed to a structural transition. We have performed temperature(T)-dependent photoelectron holography (PEH) to study dopant incorporation sites and the local structure change across the anomaly. The PEH study of Pb-LaOFBiS provided evidence for the dominant incorporation sites of Pb and F: Pb atoms are incorporated into the Bi sites and F atoms are incorporated into the O site. No remarkable difference in the local structures around Pb and Bi atoms was observed. Across the temperature of the resistivity anomaly (T), photoelectron holograms of Bi 4f changed. Comparisons of holograms with those of non-substituted LaOFBiS sample, as well as simulated holograms, suggested that (1), above T, the tetragonal structure of Pb-LaOFBiS is different from the tetragonal structure of LaOFBiS and (2), below T, the tetragonal structure still remains in Pb-LaOFBiS. We discuss a possible origin of the difference in the structure above T and the implication of the result below T, which are necessary ingredients to understand the physical properties of Pb-LaOFBiS.
铅取代的La(O,F)BiS（Pb-LaOFBiS）表现出改善的超导性能以及在100K左右的电阻率异常，这归因于结构转变。我们进行了温度（T）依赖的光电子全息术（PEH）来研究掺杂剂掺入位点以及异常区域内的局部结构变化。对Pb-LaOFBiS的PEH研究为Pb和F的主要掺入位点提供了证据：Pb原子掺入Bi位点，F原子掺入O位点。未观察到Pb和Bi原子周围局部结构的显著差异。在电阻率异常温度（T）上下，Bi 4f的光电子全息图发生了变化。将全息图与未取代的LaOFBiS样品的全息图以及模拟全息图进行比较表明，（1）在T以上，Pb-LaOFBiS的四方结构与LaOFBiS的四方结构不同；（2）在T以下，Pb-LaOFBiS中四方结构仍然存在。我们讨论了T以上结构差异的可能起源以及T以下结果的含义，这些是理解Pb-LaOFBiS物理性质的必要因素。
