Upper Critical Field, Critical Current Density and Activation Energy of the New La 1- x Sm x O 0.5 F 0.5 BiS 2 (x = 0.2, 0.8) Superconductors

Critical current density (Jc), thermal activation energy (U0), and upper critical field (Hc2) of La1−xSmxO0.5F0.5BiS2 (x = 0.2, 0.8) superconductors are investigated from magnetic field dependent ρ(T) studies. The estimated upper critical field (Hc2) has low values of 1.04 T for x = 0.2 and 1.41 T for x = 0.8. These values are lower than Sm free LaO0.5F0.5BiS2 superconductor (1.9 T). The critical current density (Jc) is estimated to be 1.35 × 105 and 5.07 × 105 A/cm2 (2 K) for x = 0.2 and 0.8 respectively, using the Bean’s model. The thermal activation energy (U0/kB) is 61 K for x = 0.2 and 140 K for x = 0.8 as calculated from Arrhenius plots at low magnetic field (1 T) and indicates a strong flux pinning potential which might be co-existing with applied magnetic field.

[1]  L. C. Gupta,et al.  Synthesis and properties of SmO0.5F0.5BiS2 and enhancement in Tc in La1-ySmyO0.5F0.5BiS2. , 2014, Inorganic chemistry.

[2]  Xiaofeng Xu,et al.  Coexistence of superconductivity and ferromagnetism inSr0.5Ce0.5FBiS2 , 2014, 1407.3711.

[3]  O. Miura,et al.  Increase in Tc and Change of Crystal Structure by High-Pressure Annealing in BiS2-Based Superconductor CeO0.3F0.7BiS2 , 2014, 1404.6361.

[4]  Zhu-An Xu,et al.  Anomalous Eu valence state and superconductivity in undoped Eu3Bi2S4F4. , 2014, Journal of the American Chemical Society.

[5]  M. Maple,et al.  Effect of yttrium substitution on the superconducting properties ofLa1-xYxO0.5F0.5BiS2 , 2014, 1410.0084.

[6]  Kai Xu,et al.  Possible charge-density wave, superconductivity, and f-electron valence instability in EuBiS 2 F , 2014, 1407.7132.

[7]  R. Jha,et al.  Appearance of bulk superconductivity under hydrostatic pressure in Sr0.5RE0.5FBiS2 (RE = Ce, Nd, Pr, and Sm) compounds , 2014, 1407.3105.

[8]  M. Nagao,et al.  High-Tc Phase of PrO0.5F0.5BiS2 single crystal induced by uniaxial pressure , 2014, 1406.3888.

[9]  R. Jha,et al.  Impact of Hydrostatic Pressure on Superconductivity of Sr0.5La0.5FBiS2 , 2014, 1402.0994.

[10]  O. Miura,et al.  Chemical pressure effect on Tc in BiS2-based Ce1−xNdxO0.5F0.5BiS2 , 2013, 1311.4272.

[11]  Xiyu Zhu,et al.  Giant superconducting fluctuation and anomalous semiconducting normal state in NdO1−xFxBi1−yS2 single crystals , 2013, 1310.0377.

[12]  M. Nagao,et al.  Structural Analysis and Superconducting Properties of F-Substituted NdOBiS2 Single Crystals , 2013, 1309.6400.

[13]  M. Maple,et al.  Pressure-induced enhancement of superconductivity and suppression of semiconducting behavior in L n O 0.5 F 0.5 BiS 2 ( L n = La ,Ce) compounds , 2013, 1307.4157.

[14]  Shruti,et al.  Structural, electromagnetic and thermoelectric properties of Bi4O4S3 superconductor , 2013, 1304.4386.

[15]  M. Maple,et al.  Superconductivity induced by electron doping in La 1-x M x OBiS 2 (M= Ti, Zr, Hf, Th) , 2013, 1303.6216.

[16]  S. Savrasov,et al.  Electron-phonon superconductivity near charge-density-wave instability in LaO0.5F0.5BiS2: Density-functional calculations , 2013 .

[17]  Y. Takahide,et al.  New Member of BiS2-Based Superconductor NdO1-xFxBiS2 , 2013 .

[18]  M. Maple,et al.  Superconductivity of F-substituted LnOBiS2 (Ln=La, Ce, Pr, Nd, Yb) compounds , 2013, 1301.3932.

[19]  Xiaofeng Xu,et al.  Superconductivity induced by La doping in Sr 1-x La x FBiS 2 , 2013, 1301.2380.

[20]  G. Huang,et al.  Phonon spectra and superconductivity of the BiS2-based compounds LaO1−xFxBiS2 , 2012, 1210.1743.

[21]  Kefeng Wang,et al.  New layered fluorosulfide SrFBiS2. , 2012, Inorganic chemistry.

[22]  Shruti,et al.  Appearance of superconductivity in layered LaO0.5F0.5BiS2 , 2012, 1207.6845.

[23]  T. Watanabe,et al.  Evolution of superconductivity in LaO1−xFxBiS2 prepared by high-pressure technique , 2012, 1209.3846.

[24]  Anuj Kumar,et al.  Synthesis and Superconductivity of New BiS2 Based Superconductor PrO0.5F0.5BiS2 , 2012, 1208.5873.

[25]  Anuj Kumar,et al.  Superconductivity at 5K in NdO0.5F0.5BiS2 , 2012, 1208.3077.

[26]  K. Kuroki,et al.  Minimal electronic models for superconducting BiS 2 layers , 2012, 1207.3888.

[27]  A. Gurevich.  Iron-based superconductors at high magnetic fields , 2011 .

[28]  Shixue Dou,et al.  Very High Critical Field and Superior Jc‐Field Performance in NdFeAsO0.82F0.18 with Tc of 51 K , 2009 .

[29]  K. A. Yates,et al.  Evidence for supercurrent connectivity in conglomerate particles in NdFeAsO1−δ , 2008, 0806.0828.

[30]  M. Cantoni,et al.  Upper critical fields well above 100 T for the superconductor SmFeAsO0.85F0.15 with T-c=46 K , 2008, 0805.2389.

[31]  Y. Nakajima,et al.  Bulk and local magnetic properties of iron-based oxypnictide superconductor SmFeAsO1-xFx (Proceedings of the international symposium on Fe-pnictide superconductors) , 2008 .

[32]  C. Poole,et al.  Handbook of Superconductivity , 1999 .

[33]  Brady,et al.  Direct observation of the critical state field profile in a YBa2Cu3O7-y single crystal. , 1992, Physical review. B, Condensed matter.

[34]  E. Helfand,et al.  Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . III. Electron Spin and Spin-Orbit Effects , 1966 .