Thickness dependence of structural and transport properties of Co-doped   BaFe2As2 on Fe buffered MgO substrates
  We have investigated the influence of the superconducting layer thickness, d, on the structural and transport properties of Co-doped BaFe2As2 films deposited on Fe-buffered MgO substrates by pulsed laser deposition. The superconducting transition temperature and the texture quality of Co-doped BaFe2As2 films improve with increasing d due to a gradual relief of the tensile strain. For d>90 nm an additional 110 textured component of Co-doped BaFe2As2 was observed, which leads to an upward shift in the angular dependent critical current density at H // c. These results indicate that the grain boundaries created by the 110 textured component may contribute to the c-axis pinning. 
Kazumasa Iida, Jens Haenisch, Sascha Trommler, Silvia Haindl, Fritz   Kurth, Ruben Huehne, Ludwig Schultz, and Bernhard Holz...
cond-mat.supr-con cond-mat.mtrl-sci