Strong pinning centers in high quality Co-doped BaFe$_{2}$As$_{2}$ epitaxial thin film grown on templated substrates

We report measurements of the field and angular dependences of the critical current density J$_{c}$ of truly Co-doped BaFe$_{2}$As$_{2}$ epitaxial thin film on SrTiO$_{3}$/(La,Sr)(Al,Ta)O$_{3}$ for different SrTiO$_{3}$ thickness, which do not exhibit any evidence of electromagnetic weak links and have $J_{c}$(4K) values exceeding 1 MA/cm$^{2}$ . Those samples show a maximum of the pinning force close to H/H$_{Irr}\sim $ 0.5 indicative of strong vortex pinning, a conclusion strengthened by a very strong c-axis peak in the angular dependence $J_{c}(\theta )$ at fields up to 12 T. In opposition to the H$_{c2}$ anisotropy, $J_{c}$ for H along the $c$-axis exceeds $J_{c}$ for field applied along the \textit{ab} plane. The microstructural origin of the strong vortex pinning has been investigated by high resolution TEM which reveals a high density of columnar defects, whose nature is currently under study.