Pulsed laser ablation of NbN/MgO/NbN multilayers

NbN/MgO/NbN multilayers have been grown by pulsed laser ablation in pure N2 and O2 atmospheres. A Nd:YAG laser, operating at λ=532 nm, pulse width 10 ns, and energy density in the range 1–2.5 J/cm2, was used. The laser beam was focused at an angle of 45° on Nb and Mg metallic targets. A rotating multiple-target holder system allowed in-situ depositions of the multilayers. The samples were grown on SrTiO3 (100) substrates 5 cm from the target and held at 550°C (NbN) and 250°C (MgO). The morphology and structure of the deposited multilayers were verified by XRD, EDS, as well as electrical measurements.