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The impact of Maki parameter and spin orbit scattering constant in the WHH model on upper critical magnetic fields in Ni-and co-doped pnictide bulk superconductors

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.5007389· OSTI ID:1565848
 [1];  [1];  [2];  [3];  [3];  [3]
  1. Saint Louis Univ., MO (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Florida State Univ., Tallahassee, FL (United States)
+ Show Author Affiliations
Werthamer, Helfand, and Hohenberg (WHH) model is applied to the measured upper critical magnetic fields of Ni-and Co-doped pnictide bulk superconductors. This approach incorporates both orbital and paramagnetic effects in the upper critical field’s temperature dependence. Additionally, the relative importance of both the orbital and paramagnetic effects in the suppression of the superconductivity is described by the Maki parameter. In most superconductors, the Maki parameter is usually much less than unity suggesting that the influence of the paramagnetic effect is small. However, in materials with heavy electron effective mass, in which the Fermi energy is small, or in layered materials in a magnetic field parallel to the layers, the Maki parameter can be larger than unity. This is the case for our bulk pnictides. By fitting the measured temperature dependence of the upper critical field, we derive the Maki parameter and the spin orbit scattering constant and examine the correlation between the Maki parameter, the spin orbit scattering constant, and the reduced upper critical field for our curve fits vs. temperature. In conclusion, the obtained Maki parameters indicate that the Zeeman pair breaking dominates over the orbital pair breaking and spin-paramagnetic pair-breaking effect is significant. At the same time, our spin orbit scattering constants indicate that spin-orbit scattering needs to be also included in description of the Hc2(T) data in these materials.
Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
89233218CNA000001
OSTI ID:
1565848
Report Number(s):
LA-UR--17-28058
Journal Information:
AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Vol. 1895; ISSN 0094-243X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (16)

Upper Critical and Irreversibility Fields in Ba(Fe0.95Ni0.05)2As2 and Ba(Fe0.94Ni0.06)2As2 Pnictide Bulk Superconductors journal September 2016
Upper Critical and Irreversibility Fields in Ba(Fe0.92Co0.08)2As2 and Ba(Fe0.91Co0.09)2As2 Pnictide Bulk Superconductors journal September 2016
Universal behavior of the upper critical field in iron-based superconductors journal December 2011
Limits of the upper critical field in dirty two-gap superconductors journal June 2007
Nearly isotropic superconductivity in (Ba,K)Fe2As2 journal January 2009
Superconductivity in a Strong Spin-Exchange Field journal August 1964
Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . II journal July 1966
Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . III. Electron Spin and Spin-Orbit Effects journal July 1966
Effect of Pauli Paramagnetism on Magnetic Properties of High-Field Superconductors journal August 1966
Enhancement of the upper critical field by nonmagnetic impurities in dirty two-gap superconductors journal May 2003
High-field superconductivity in alloyed Mg B 2 thin films journal January 2005
Effects of two gaps and paramagnetic pair breaking on the upper critical field of SmFeAsO 0.85 and SmFeAsO 0.8 F 0.2 single crystals journal October 2009
Upper critical field and the Fulde-Ferrel-Larkin-Ovchinnikov transition in multiband superconductors journal November 2010
Anisotropic upper critical field and possible Fulde-Ferrel-Larkin-Ovchinnikov state in the stoichiometric pnictide superconductor LiFeAs journal February 2011
Upper critical field of NaFe 1 − x Co x As superconductors journal February 2014
Anisotropy of the Upper Critical Field in a Co-Doped BaFe 2 As 2 Single Crystal journal August 2009

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Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
High Magnetic Field Science
Maki parameter
pnictide superconductors