  We demonstrate the growth of epitaxial Fe/Ba(Fe(1-x)Co(x))2As2 (Fe/Ba-122)
bilayers on MgO(001) and LSAT(001) single crystal substrates using Pulsed Laser
Deposition (PLD). By exploiting the metallic nature of the FeAs tetrahedron in
the Ba-122 crystal structure, we achieve a coherent interfacial bond between
bcc iron and Co-doped Ba-122. Tc values for both bilayers were close to that of
the PLD target. Direct observation of interfacial bonding between Fe and the
Ba-122 FeAs sublattice by atomic resolution transmission electron microscopy
implies that this bilayer architecture may work for other iron pnictide systems
and pave the way for the fabrication of superconducting/ferromagnetic
heterostructures.
