激光分子束外延BaTiO3薄膜最顶层表面原子平面与薄膜生长机理

用激光分子束外延技术在SrTiO₃(001)衬底上外延生长了高质量的BaTiO_{3< /sub>薄膜，薄膜的生长过程由反射式高能电子衍射仪(RHEED)原位实时监测，表明薄膜具有 二维层状生长模式.薄膜的晶体结构和表面形貌分别由X射线衍射和原子力显微镜表征，显示 该薄膜为完全c轴取向四方相晶体结构，其表面具有原子尺度光滑性.采用角分辨X射线光电 子谱技术(ARXPS)，研究了BaTiO3薄膜表面最顶层原子种类和排列状况.结果表 明，BaTiO3 关键词： 激光分子束外延 3薄膜')" href="#">氧化物BaTiO3薄膜 最顶层表面 角分辨X射线光电子谱}

TOPMOST SURFACE AND GROWTH MECHANISM OF BaTiO3 THIN FILM GROWN BY LAS ER MOLECULAR BEAM EPITAXY

The BaTiO₃ thin film was grown epitaxially on SrTiO₃(001) substrate by laser molecular beam epitaxy (laser-MBE). The film growth process w as monitored by in situ reflection high-energy electron diffraction (RHEED), the regular RHEED intensity oscillation from the 0th-Bragg reflection shows an unit cell layer-by-layer growth mode. The crystalline structure and the surface morp hology of the laser-MBE BaTiO₃ film were characterized by X-ray diffr action (XRD) and by atomic force microscopy (AFM), respectively. The XRD and AFM results show that laser-MBE BaTiO₃ film exhibit the tetragonal c-axi s oriented structure and an atomically smooth surface with a root mean square su rface roughness of 016nm. The topmost surface of the film was studied by angl e-resolved X-ray photoelectron spectroscopy (ARXPS), indicating the laser-MBE Ba TiO₃ film is predominantly terminated with TiO₂ atomic pla ne. The topmost surface of laser-ablated BaTiO₃ film was also analyze d. The film growth mechanism was investigated in atomic scale.