在SrTiO3（001）衬底上层状生长超薄LaCoO3薄膜

We have studied the epitaxial growth of LaCoO3 films on SrTiO3(001) substrate by pulsed laser deposition (PLD) method. Reflection high-energy electron diffraction (RHEED) patterns and intensity oscillations indicate that the two-dimensional layer-by-layer growth for initial 2 unit cell (u.c.) thick film. The film growth transfers to three-dimensional island growth at a critical film thickness of 3 u.c. to relieve the strain, due to the large lattice mismatch of 2.63% between LaCoO3 film and SrTiO3 substrate. The morphology of films investigated by atomic force microscopy (AFM) confirms the film growth mode transition from layer-by-layer to island mode. The magnetic measurement shows that the corresponding ferromagnetic moment per Co ion of 2 u.c. tensile films is more than six times larger than that of 20 u.c. lattice-relaxed films