Anisotropy of superconducting single crystal SmFeAsO_(0.8)F_(0.2) studied by torque magnetometry

Abstract

Single crystals of the oxypnictide superconductor SmFeAsO_(0.8)F_(0.2) with T_c=45(1) K were investigated by torque magnetometry. The crystals of mass~0.1 mug were grown by a high-pressure cubic anvil technique. The use of a high-sensitive piezoresistive torque sensor made it possible to study the anisotropic magnetic properties of these tiny crystals. The anisotropy parameter was found to be field independent, but varies strongly with temperature ranging from 8 at T=T_c to 23 at T=0.4T_c. This unusual behavior signals unconventional superconductivity.

accepted for publication in J. Supercond. Nov. Magn

References in corpus (18)

• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO${}_{1-x}$F${}_x$FeAs
• Superconductivity in iron-based F-doped layered quaternary compound Nd[O1-xFx]FeAs
• Very High Field Two-Band Superconductivity in LaFeAsO_0.89F_0.11
• Commensurate Spin Density Wave in LaOFeAs: A Local Probe Study
• Spin-singlet superconductivity with multiple gaps in PrO0.89F0.11FeAs
• Field and Temperature Dependence of the Superfluid Density in LaO_{1-x}F_xFeAs Superconductors: A Muon Spin Relaxation Study
• Critical Fields and Anisotropy of NdO0.82F0.18FeAs Single Crystals
• Hall effect and magnetoresistance in the normal state of the superconductor LaO${}_{0.9}$F${}_{0.1-x}$FeAs
• Upper critical field, Hall effect and magnetoresistance in the iron-based layered superconductor LaFeAsO_{0.9}F_{0.1-δ}
• Superconductivity at 36 K in Gadolinium-arsenide Oxides GdO${}_{1-x}$F${}_x$FeAs
• Single crystal of superconducting SmFeAsO1-xFy grown at high pressure
• Point-Contact Spectroscopy of Iron-Based Layered Superconductor LaO${}_{0.9}$F${}_{0.1-\delta }$FeAs
• Muon-spin rotation studies of SmFeAsO_0.85 and NdFeAsO_0.85 superconductors
• Universal observation of multiple order parameters in cuprate superconductors
• Superconducting energy gap and c-axis plasma frequency of (Nd,Sm)O0.82F0.18FeAs superconductors from infrared ellipsometry
• Comment on ``Anisotropic s-wave superconductivity: comparison with experiments on MgB_2 [A. I. Posazhennikova, T. Dahm and K. Maki, cond-mat/0204272; submitted to Europhys. Lett.]

Cited by in corpus (17)

• Magnetic penetration depth of single crystal SmFeAsO_{1-x}F_y: a fully gapped superconducting state
• Superconductivity at 23 K and Low Anisotropy in Rb-Substituted BaFe_2As_2 Single Crystals
• Th substituted SmFeAsO: structural details and superconductivity with Tc above 50 K
• Point-contact Andreev-reflection spectroscopy in ReFeAsO_{1-x}F_x (Re = La, Sm): Possible evidence for two nodeless gaps
• Evidence for two distinct anisotropies in the oxypnictide superconductors SmFeAsO_(0.8)F_(0.2) and NdFeAsO_(0.8)F_(0.2)
• Point contact Andreev reflection spectroscopy of NdFeAsO_0.85
• Anisotropic Phase Diagram and Superconducting Fluctuations in SmFeAsO0.85F0.15
• Anisotropy of iron-platinum-arsenide Ca10(PtnAs8)(Fe2-xPtxAs2)5 single crystals
• Anisotropy induced vortex lattice rearrangement in CaKFe${}_4$As${}_4$
• Large $D-2$ Theory of Superconducting Fluctuations in a Magnetic Field and its Application to Iron-Pnictides
• Anisotropy of the superconducting state parameters and intrinsic pinning in low-level Pr-doped YBa2Cu3O(7-delta) single crystals
• Superconducting Order Parameter and Bosonic Mode in Hydrogen-Substituted NdFeAsO${}_{0.6}$H${}_{0.36}$ Revealed by Multiple Andreev Reflection Spectroscopy
• Evidence for a temperature dependent anisotropy of the superconducting state parameters in underdoped SmBa2Cu3Ox
• Magnetic torque study of the temperature dependent anisotropy parameter in overdoped superconducting single-crystal YBa_2Cu_3O_7
• Vortex dynamics and second magnetization peak in the iron-pnictide superconductor Ca${}_{0.82}$La${}_{0.18}$Fe${}_{0.96}$Ni${}_{0.04}$As${}_2$
• Second magnetization peak, anomalous field penetration, and Josephson vortices in KCa${}_2$Fe${}_4$As${}_4$F${}_2$ bilayer pnictide superconductor
• Critical current oscillations in the intrinsic hybrid vortex state of SmFeAs(O,F)