Effect of substrate on the epitaxial growth of borocarbide thin films

The influence of the substrate on the epitaxial growth of borocarbide thin films was extensively studied. LuNi2B2C thin films were deposited by pulsed laser ablation from a stoichiometry target in high vacuum condition on different kind of substrates. Different cuts of MgO crystals with different surface crystallographic symmetry were employed. All the samples show a good c-axis orientation and rocking curves around LuNi2B2C (004) reflection show important differences both in width and in shape for the samples deposited on the different substrates. The growth of the film is effectively driven by the substrate even in the case of big lattice mismatch as in the case of MgO substrates. Different behaviors of the in-plane texture were observed on the different MgO cuts: an almost perfect epitaxial growth was obtained on the MgO (110) whereas multiple in-plane orientations are present on MgO (100) and (111). These results and all the observed orientations are well explained and understood in term of a simple geometrical near-coincident site lattice model (NCSL). A correlation between structural and superconducting properties is observed and the properties of best samples are similar to monocrystals ones (T-c=16.4 K Delta T-c=0.3 K