Conductive metallic LaNiO3 films from metallo-organic precursors

Conductive metallic LaNiO3 (LNO) films were prepared by metallo-organic decomposition. 2-Ethylhexanoates of lanthanum and nickel were synthesized as the metallo-organic precursors. The films were obtained by spin-on pyrolysis in air on various substrates and then annealing at various temperature in oxygen or air. Thermogravimetric analysis, inductively coupled plasma analysis, X-ray diffraction, transmission electron microscopy, Rutherford backscattering spectrometry and electrical measurements were used to determine the synthesis process and the characterization of the films. The effect of different thermal treatments, annealing temperature and substrates on crystallinity, orientation and conductive behavior of LNO films was studied. The results indicated the pyrolysis process is the critical step to obtain good metallic LNO films at lower grown temperature. Epitaxial metallic LNO films could be fabricated on SrTiO3 (STO). The trend of resistance as a function of annealing temperature of LNO films on STO, fused quartz and Si substrates showed LNO films on STO have lower crystalline temperature and higher transition temperature from conductor to insulator than on fused quartz and Si. (C) 1997 Elsevier Science S.A.