2.2. Material characterization The thickness of the as-deposited film was examined by an Atomic Force Microscope (Vee co Nano scope). Limited to the sample size requirement of the apparatus, the step which was formed by removing the adhesive tape on the silicon wafer was measured to confirm the thickness of the film.The X-ray diffraction pattern of the aged and annealed film were directly obtained at room temperature on a diffractometer(X’ Pert PRO, PANalytical B.V.) with Cu K ( = 1.540598˚A) radiation. A standard –2 mode was selected with 2 ranging from 30◦to 80◦in step of 0.02◦.