Growth of polycrystalline La0.5Sr0.5CoO3 films by femtosecond pulsed laser deposition

In this paper we present the growth of La0.5Sr0.5CoO3 (LSCO) films on MgO, quartz, and silicon substrates by pulsed laser deposition (PLD) using a Ti : sapphire laser (50 fs, 800 nm wavelength). The morphology and the structure of the films were studied by X-ray diffraction, atomic force microscopy, and scanning electron microscopy. The films were polycrystalline and exhibit a good adherence to the Si substrate. Different deposition parameters such as substrate temperature, oxygen pressure, and laser fluence were varied to achieve good surface quality and low resistivity crystalline films. We also defined the optimum conditions in which the deposited film surface is particulate free. The best films (droplets free) were grown at 625 °C, in an ambient oxygen pressure of 6 mbar, with an incident laser fluence of 0.19 J/cm2. This is a mandatory step in the complex work of fabricating La0.5Sr0.5CoO3/BaTiO3/La0.5Sr0.5CoO3 heterostructures for the development of thin film capacitors for non-volatile ferroelectric access memory devices.