Transport characteristics of Co-doped BaFe$_{2}$As$_{2}$ epitaxial thin film 24deg grain-boundaries

We investigate [001] 24deg tilt GBs of epitaxial thin film of the pnictide superconductor Co-doped Ba(Fe$_{0.92}$Co$_{0.08})_{2}$As$_{2}$ on (001) SrTiO$_{3}$ bicrystal substrates. The films were grown by pulsed laser deposition (PLD) with KrF (248 nm) UW excimer laser in vacuum at a base pressure of 2x10$^{-7}$ Torr. The chemical composition of the films determined by wavelength dispersive x-ray spectroscopy (WDS) is Ba : Fe : Co : As : O = 1 : 1.7 : 0.13 : 1.7 : 0.3. Four-circle x-ray diffraction exhibits excellent expitaxy with cube-on cube in-plane epitaxial relationship. The films have an onset T$_{c}$ of 20.5~K, and a T$_{co}$ of 19.8K. The intragrain $J_{c}$ is over 1 MA/cm$^{2}$ (4.2K, self field) which is significantly higher than in previously reported thin films. The grain boundary couples at a slightly lower temperature of 19.7~K. We discuss magnetic field and temperature dependence of the IV characteristics, and microwave response.