Anomalous local magnetic field distribution and strong pinning in CaFe1.94Co0.06As2 single crystals

Abstract

Magneto-optical imaging of a single crystal of CaFe1.94Co0.06As2, shows anomalous remnant magnetization within Meissner like regions of the superconductor. The unconventional shape of the local magnetization hysteresis loop suggests admixture of superconducting and magnetic fractions governing the response. Near the superconducting transition temperature, local magnetic field exceeds the applied field resulting in a diamagnetic to positive magnetization transformation. The observed anomalies in the local magnetic field distribution are accompanied with enhanced bulk pinning in the CaFe1.94Co0.06As2 single crystals. We propose our results suggest a coexistence of superconductivity and magnetic correlations.

arXiv comment6 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1201.3693

References in corpus (19)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Coexistence of static magnetism and superconductivity in SmFeAsO1-xFx as revealed by muon spin rotation
• The Unprecedented Giant Coupling of Fe-spin State and the As-As Hybridization in Iron-Pnictide
• Electronic phase separation in the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe(2)As(2)
• Where does the transport current flow in Bi2Sr2CaCu2O8 crystals?
• Evidence for two distinct scales of current flow in polycrystalline Sm and Nd iron oxypnictides
• Flux pinning in (1111) iron-pnictide superconducting crystals
• Muon spin relaxation studies of magnetic order and superfluid density in antiferromagnetic NdOFeAs, BaFe2As2 and superconducting (Ba,K)Fe2As2
• Anisotropic magnetic and superconducting properties of pure and Co-doped CaFe${}_2$As${}_2$ single crystals
• Nernst effect in single crystals of the pnictide superconductor CaFe1.92Co0.08As2 and parent compound CaFe2As2
• Magneto-optical study of Ba(Fe${}_{1-x}$T${}_x$)${}_2$As${}_2$ (T=Co, Ni) single crystals irradiated with heavy-ions
• Symmetry and disorder of the vitreous vortex lattice in an overdoped BaFe_{2-x}Co_xAs_2 superconductor: Indication for strong single-vortex pinning
• Muon spin rotation study of magnetism and superconductivity in BaFe2-xCoxAs2 and Pr1-xSrxFeAsO
• Superconductivity and Field-Induced Magnetism in SrFe_1.75Co_0.25As_2
• Anomalous Meissner effect in pnictide superconductors

Cited by in corpus (1)

• High sensitivity differential Magneto-Optical Imaging with a compact Faradaymodulator