Effect of interface structure on the chemical composition and electrical properties of sol-gel-derived LaNiO₃ films

In the present work, lanthanum nickel oxide (LNO) thin films are prepared with the sol-gel multilayer coating method. Lattice-matched SrTiO₃ (STO) buffer layer is introduced to tailor the film-substrate interface. The effect of interface structure on the electrical properties, microstructure and chemical composition of LNO films is investigated. The results show that the improvement in the interface structure minimizes the effect of interface on the electrical properties of LNO films and leads to a sharp decrease in room-temperature resistivity of LNO films to 570 μΩ cm, comparable to that of the LNO films on single-crystal STO substrate. This is ascribed to the decrease in structural disorder and the concentration of oxygen vacancies in the LNO films. (orig.)