Giant increase of critical current density and vortex pinning in Mn doped K{sub x}Fe{sub 2−y}Se{sub 2} single crystals

Journal Article · Mon Nov 10 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4901902· OSTI ID:22391960

Li, Mingtao; Zhang, Jincang ^[1]; Chen, La ^[1]; You, Wen-Long ^[2]; Ge, Junyi ^[3]

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1. Department of Physics, Shanghai University, Shanghai 200444 (China)
2. College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006 (China)
3. INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)

We report a comparative study of the critical current density (J{sub c}) and vortex pinning among pure and Mn doped K{sub x}Fe{sub 2−y}Se{sub 2} single crystals. It is found that the J{sub c} values can be greatly improved by Mn doping and post-quenching treatment when comparing to pristine pure sample. In contrast to pure samples, an anomalous second magnetization peak (SMP) effect is observed in both 1% and 2% Mn doped samples at T = 3 K for H∥ab but not for H∥c. Referring to Dew-Hughes and Kramer's model, we performed scaling analyses of the vortex pinning force density vs magnetic field in 1% Mn doped and quenched pristine crystals. The results show that the normal point defects are the dominant pinning sources, which probably originate from the variations of intercalated K atoms. We propose that the large nonsuperconducting K-Mn-Se inclusions may contribute to the partial normal surface pinning and give rise to the anomalous SMP effect for H∥ab in Mn doped crystals. These results may facilitate further understanding of the superconductivity and vortex pinning in intercalated iron-selenides superconductors.

• OSTI ID: 22391960
• Journal Information: Applied Physics Letters, Vol. 105, Issue 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CLATHRATES
CRITICAL CURRENT
CURRENT DENSITY
DOPED MATERIALS
IRON SELENIDES
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIZATION
MANGANESE
MONOCRYSTALS
POINT DEFECTS
POTASSIUM
QUENCHING
SELENIUM
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TEMPERATURE RANGE 0000-0013 K
VORTICES