fig6

Figure 6. SEM images of superconducting layers with different Eu doping levels. (A) SEM image when Eu doping amount is 0. (B) SEM image when Eu doping amount is 0.1. (C) SEM image when Eu doping amount is 0.3. (D) SEM image when Eu doping amount is 0.5^[98] © Springer Science+Business Media New York 2016.