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

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Cited by in corpus (5)

• 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
• 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