Doubling the critical current density in superconducting FeSe0.5Te0.5 thin films by low temperature oxygen annealing

Iron chalcogenidesuperconducting thin films and coatedconductors are attractive for potential high field applications at liquid helium temperature for their high critical current densitiesJc, low anisotropies, and relatively strong grain couplings. Embedding flux pinning defects is a general approach to increase the in-field performance ofsuperconductors. However, many effective pinning defects can adversely affect the zero field or self-fieldJc, particularly in cuprate high temperaturesuperconductors. Here, we report the doubling of the self-fieldJc in FeSe0.5Te0.5films by low temperature oxygenannealing, reaching ∼3 MA/cm2. In-field performance is also dramatically enhanced. Our results demonstrate that low temperature oxygenannealing is a simple and cost-efficient post-treatment technique which can greatly help to accelerate the potential high field applications of the iron-basedsuperconductors.

Source: Applied Physics Letters - November 16, 2016 Category: Physics Authors: Cheng Zhang, Weidong Si and Qiang Li Source Type: research