Artificially Engineered Nanostrain in Iron Chalcogenide Superconductor Thin Film for Enhancing Supercurrent

Abstract

Although nanoscale deformation, such as nanostrain in iron chalcogenide (FeSexTe1-x, FST) thin films, has attracted attention owing to the enhancement of general superconducting properties, including critical current density (Jc) and critical transition temperature, its formation has proven to be an extremely challenging and complex process thus far. Herein, we successfully fabricated an epitaxial FST thin film with uniformly distributed nanostrain by injection of a trace amount of CeO2 inside FST matrix using sequential pulsed laser deposition. Using transmission electron microscopy and geometrical phase analysis, we verified that a trace amount of CeO2 injection forms nanoscale fine defects with a nanostrained region, which has a tensile strain (ezz ~ 0.02) along the c-axis of the FST matrix. The nanostrained FST thin film achieves a remarkable Jc of 3.5 MA/cm2 for a self-field at 6 K and a highly enhanced Jc under the entire magnetic field with respect to a pristine FST thin film.

arXiv comment25 pages, 8 figures

References in corpus (10)

• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• New Fe-based superconductors: properties relevant for applications
• Template engineering of Co-doped BaFe2As2 single-crystal thin films
• Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe${}_{1-x}$Te${}_x$ thin films
• Artificially engineered superlattices of pnictide superconductor
• Imaging atomic-scale effects of high-energy ion irradiation on superconductivity and vortex pinning in Fe(Se,Te)
• Intrinsic pinning and the critical current scaling of clean epitaxial Fe(Se,Te) thin films
• Oxypnictide SmFeAs(O,F) superconductor: a candidate for high-field magnet applications
• Nanoscale interplay of strain and doping in a high-temperature superconductor
• The influence of the in-plane lattice constant on the superconducting transition temperature of FeSe0.7Te0.3 thin films