Real-time x-ray reflectivity and diffraction measurements under in situ sputtering conditions were employed to study the growth behavior of LaNiO_3 thin films on a Si substrate. Our results clearly show there is a transition layer of 60A, which grew in the first 6 mm of deposition. The in situ x-ray-diffraction patterns indicated that this transition layer is amorphous. Subsequently, a polycrystalline overlayer grew as observed from the in situ x-ray reflectivity curves and diffraction patterns. Nucleation and growth took place on this transition layer with random orientation and then the polycrystalline columnar textures of (100) and (110) grew on the top of this random orientation layer. By comparing the integrated intensities of two Bragg peaks in the plane normal of x-ray diffraction, it was found that a crossover of the growth orientation from the (l10) to the (100) direction occurred and the ability of (100) texturization enhanced with increasing film thickness beyond a certain critical value.
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