LANTHANUM CALCIUM MANGANITE GROWN BY LASER ABLATION: OPTIMISATION OF THE DEPOSITION PARAMETERS

Lanthanum manganite doped with alkaline earths have become of interest for their magneto resistive properties. Pulsed laser ablation has been very successful in the preparation of a wide range of perovskite type oxides and is proving to be particularly useful in this case. A study of the process parameters which affect the structure and morphology of the film is presented. LaO.67CaO.33Mn03 has been grown on SrTi03 using an XeCl excimer laser; some of the films were later processed under different pressures of oxygen at 950 °C. The effect of growth temperature, laser pulse energy and oxygen annealing pressure were investigated using X ray diffraction and electron microscopy. Highly oriented growth was observed in samples grown below 700 °C in the (200) direction, coincident with the substrate orientation. The samples grown at higher temperature are polycrystalline and their crystalline order improves with post-growth annealing at 950 °C in an oxygen flux.