Paris E, Mizuguchi Y, Hacisalihoglu M Y, Hiroi T, Joseph B, Aquilanti G, Miura O, Mizokawa T, Saini N L
Dipartimento di Fisica, Università di Roma 'La Sapienza', P. le Aldo Moro 2, 00185 Roma, Italy. Center for Life NanoScience@Sapienza, Istituto Italiano di Tecnologia, V. le Regina Elena 291, 00185 Rome, Italy.
J Phys Condens Matter. 2017 Apr 12;29(14):145603. doi: 10.1088/1361-648X/aa5e97. Epub 2017 Feb 6.
We have studied the local structure of LaOFBiS Se by Bi L-edge extended x-ray absorption fine structure (EXAFS). We find a significant effect of Se substitution on the local atomic correlations with a gradual elongation of average in-plane Bi-S bondlength. The associated mean square relative displacement, measuring average local distortions in the BiS plane, hardly shows any change for small Se substitution, but decreases significantly for [Formula: see text]. The Se substitution appears to suppress the local distortions within the BiS plane that may optimize in-plane orbital hybridization and hence the superconductivity. The results suggest that the local structure of the BiS-layer is one of the key ingredients to control the physical properties of the BiS-based dichalcogenides.
我们通过铋L边扩展X射线吸收精细结构（EXAFS）研究了LaOFBiS Se的局部结构。我们发现，随着平均面内Bi-S键长逐渐延长，硒取代对局部原子相关性有显著影响。用于测量BiS平面内平均局部畸变的相关均方相对位移，对于小的硒取代几乎没有变化，但对于[公式：见原文]则显著减小。硒取代似乎抑制了BiS平面内的局部畸变，而这种畸变可能会优化面内轨道杂化从而提高超导性。结果表明，BiS层的局部结构是控制基于BiS的二硫属化物物理性质的关键因素之一。
