Bulletin of the American Physical Society
APS March Meeting 2018
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session V11: Fe-based superconductors - Material synthesis and discovery
2:30 PM–5:18 PM,
Thursday, March 8, 2018
LACC Room: 303A
Sponsoring Unit: DMP
Chair: Brian Sales, Oak Ridge National Lab
Abstract: V11.00001 : Progress and perspectives in materials chemistry of iron-based superconductors*
2:30 PM–3:06 PM
(Chemistry, LMU München)
(Chemistry, LMU München)
My talk reviews discoveries and recent developments of superconducting iron based compounds from the view of materials chemistry. Initiated by the first observations of superconductivity in the pnictide-oxides LaFePO (2006) and LaFeAsO1-xFx (2008), tremendous activities have meanwhile spawned an impressive family of iron-based superconducting materials, which is not inferior to the cuprates. Superconductivity in iron-based compounds emerges in Fe2X2 layers (X = As, P, Se, S) as the common structural motif. It is intriguing how combinations of these active layers with a variety of separating blocking layers yielded many new superconductors with partly novel crystal structures, for example (CaFeAs)10Pt4As8 with Tc up to 40 K. Remarkable combinations of separating layers occur in the recently discovered self-doped compounds RbFe2As2[GdOFeAs]2 and KFe2As2[CaFFeAs]2. Subtle manipulations of the Fe2X2 or the blocking layers by doping control the superconducting properties. Especially the 122-type compounds based on BaFe2As2 proved to be extremely adaptive to doping. Superconductivity in iron arsenides emerges during destabilization of antiferromagnetism by doping or pressure, while the intertwining with magnetism is less clear in iron selenides where nematic magnetism plays a role. The exciting discovery of superconductivity up to Tc = 100 K in FeSe single layers on STO raised the question if wide separation of FeSe layers by intercalation may also produce such high Tc. For example [(Li1-xFex)OH]FeSe exhibits Tc = 42 K and shows the rare coexistence of ferromagnetism and superconductivity. In spite of this rich crystal chemistry, the highest Tc in iron based bulk materials is currently 55 K. However, since the true factors for high Tc are not yet understood, only explorative synthesis of further iron based or related systems can pave the way to higher Tc above the important 77 K threshold.
*This work was financially supported by the German Research Foundation (DFG).
The American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics.
1 Physics Ellipse, College Park, MD 20740-3844
Editorial Office 1 Research Road, Ridge, NY 11961-2701 (631) 591-4000
Office of Public Affairs 529 14th St NW, Suite 1050, Washington, D.C. 20045-2001 (202) 662-8700