NdSrNi0.8Cu0.2O4−δ thin films epitaxially grown by pulsed laser deposition on LaAlO3 and SrTiO3: A potential electrode for epitaxial regrowth of perovskite structure-based oxides

NdSrNi0.8Cu0.2O4−δ (NSNCO) thin films were grown by pulsed laser deposition (PLD) on LaAlO3 and (1 1 0)SrTiO3 substrates. NSNCO thin films were (0 0 l) and (1 0 3) oriented on (1 0 0) LaAlO3 and (1 1 0)SrTiO3, respectively, as evidenced by the θ−2θ X-ray diffraction. The high crystalline quality was illustrated by low value of rocking curve (Δω=0.1–0.5° for (0 0 l) films and about 1° for (1 0 3) films). In-plane ordering was probed by X-ray diffraction ϕ-scans, evidencing the epitaxial growth on both substrates. The microstructure of films investigated by scanning electron microscopy was strongly influenced by deposition conditions. Four probe electrical resistivity measurements were performed versus temperature in the range 77–300 K. The resistivity was found to be 0.004 Ω cm at room temperature. Some bilayers combining a ferroelectric oxide and NSNCO, i.e. SrBi2Nb2O9 (SBN) and NdSrNi0.8Cu0.2O4−δ, were grown by PLD on both substrates. The possibility to control (0 0 l)- and (1 1 6)-oriented epitaxial SBN thin films was proved by the X-ray diffraction analysis.