Coexistence of ferromagnetism, antiferromagnetism, and superconductivity in magnetically anisotropic (Eu,La)FeAs2

Abstract

Materials with exceptional magnetism and superconductivity usually conceive emergent physical phenomena. Here, we investigate the physical properties of the (Eu,La)FeAs2 system with double magnetic sublattices. The parent EuFeAs2 shows anisotropy-associated magnetic behaviors, such as Eu-related moment canting and exchange bias. Through La doping, the magnetic anisotropy is enhanced with ferromagnetism of Eu2+ realized in the overdoped region, and a special exchange bias of the superposed ferromagnetic/superconducting loop revealed in Eu0.8La0.2FeAs2. Meanwhile, the Fe-related antiferromagnetism shows unusual robustness against La doping. Theoretical calculation and 57Fe Mössbauer spectroscopy investigation reveal a doping-tunable dual itinerant/localized nature of the Fe-related antiferromagnetism. Coexistence of the Eu-related ferromagnetism, Fe-related robust antiferromagnetism, and superconductivity is further revealed in Eu0.8La0.2FeAs2, providing a platform for further exploration of potential applications and emergent physics. Finally, an electronic phase diagram is established for (Eu,La)FeAs2 with the whole superconducting dome adjacent to the Fe-related antiferromagnetic phase, which is of benefit for seeking underlying clues to high-temperature superconductivity.

13 pages, 6 figures for the main text

References in corpus (15)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Coexistence of the spin-density-wave and superconductivity in the (Ba,K)Fe2As2
• Coexistence of static magnetism and superconductivity in SmFeAsO1-xFx as revealed by muon spin rotation
• Doping evoluton of antiferromagnetic order and structural distortion in LaFeAsO${}_{1-x}$F${}_x$
• Observation of tunable exchange bias in Sr${}_2$YbRuO${}_6$
• Shape of spin density wave versus temperature in AFe2As2 (A=Ca, Ba, Eu): A Mössbauer study
• Interplay between Fe and Nd magnetism in NdFeAsO single crystals
• Incommensurate spin density wave in Co-doped BaFe2As2
• Enhancement of Superconductivity by Exchange Bias
• A large moment antiferromagnetic order in overdoped high-Tc superconductor 154SmFeAsO1-xDx
• Phase diagram of Eu magnetic ordering in Sn-flux-grown Eu(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ single crystals
• Discovery of a novel 112-type iron-pnictide and La-doping induced superconductivity in Eu1-xLaxFeAs2 (x = 0 ~ 0.15)
• Co-doping effects on magnetism and superconductivity in the 112-type EuFeAs2 system

Cited by in corpus (2)

• Topological Superconductivity from Unconventional Band Degeneracy with Conventional Pairing
• Epitaxial Integration of a Perpendicularly Magnetized Ferrimagnetic Metal on a Ferroelectric oxide for Electric-Field Control