OXYGEN-PRESSURE DEPENDENCE OF MORPHOLOGY OF LA2-XSRXCUO4 ULTRA-THIN FILMS

La2-xSrxCuO4 ultra-thin films with thickness 200 Angstrom were fabrica ted by pulsed laser deposition method in oxygen (O-2) atmosphere. The morphology of deposited films was investigated by reflection high ener gy electron diffraction (RHEED), atomic force microscopy (AFM) and sca nning electronic microscopy (SEM). The strong oxygen ambient pressure dependence of film morphology was observed. In high oxygen ambient pre ssure, the film growth is dominated by island growth mode. The results imply that the experimental conditions of oxygen ambient pressure and substrate temperature are critical for the layer-by-layer growth mode .