Role of the local structure in superconductivity of LaO0.5F0.5BiS2−xSex system. (6th March 2017)

• Record Type: Journal Article
• Authors: Paris, E; Mizuguchi, Y; Hacisalihoglu, M Y; Hiroi, T; Joseph, B; Aquilanti, G; Miura, O; Mizokawa, T; Saini, N L
• Is Part Of: Journal of physics. Volume 29:Number 14(2017)
• Publication Date: 2017-03-06
• Subjects: BiS2-based superconductors -- effect of substitution -- local structure and disorder; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aa5e97
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We have studied the local structure of LaO0.5 F0.5 BiS2− x Se x by Bi L1 -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 BiS2 plane, hardly shows any change for small Se substitution, but decreases significantly for x ⩾ 0.6 . The Se substitution appears to suppress the local distortions within the BiS2 plane that may optimize in-plane orbital hybridization and hence the superconductivity. The results suggest that the local structure of the BiS2 -layer is one of the key ingredients to control the physical properties of the BiS2 -based dichalcogenides.