Fabrication of their properties

该项目旨在建立必要的技术，以制造从无机到无机，从绝缘体到超导体的各种材料之间的高度异质晶体结构。新的物理性质正在从这些奇特的结构中发现。(1)在GaAs衬底上制备岩盐氧化物薄膜的复合异质结构通过在GaAs（001）衬底上制备具有两个碱金属卤化物缓冲层的复合异质结构，在GaAs（001）衬底上生长了单晶MgO薄膜。与直接在GaAs（001）衬底上生长MgO相比，生长温度降低到150℃。生长的薄膜的电子能量损失谱与体相MgO的电子能量损失谱一致，表明保持了表面化学计量比。在超高真空条件下，该结构在600℃以下仍保持稳定。复杂异质结构的概念将有助于在GaAs衬底上制备功能氧化层，并导致氧化物/半导体集成器件。(2)液相外延生长与相变 关于我们 在单晶无机基底上的液晶单层膜有望揭示涉及二维相变的新性质。发现液晶12 CB可以在碱金属卤化物（OO 1）表面上外延生长。利用高灵敏度反射高能电子衍射和原子力显微镜研究了薄膜结构的温度依赖性。在12 CB的转变温度附近，单层边界的形状随着衬底温度的变化而急剧变化。(3)选择性生长是目前唯一能够大规模制备结构清晰的分子材料纳米结构的方法。膜-基界面稳定能的差异是实现高选择性的关键。制定了两项指导原则。一种是使用生长的膜和在离子基底材料中发现的基底材料的晶格匹配。另一种是使用不同的货车德瓦尔斯相互作用，这是发现使用分层材料。(4)薄膜和异质结构的物理性质测量了制造结构的物理性质，并揭示了新的性质。例如，由于分子排列的不同，MnPc薄膜表现出与大块单晶不同的磁性。少

This project has aimed at establishing techniques necessary to fabricate highly heterogeneous crystalline structures among various materials from inorganic to inorganic and from insulators to superconductors. Novel physical properties are being found from those exotic structures.(1) A complex heterostructure to achieve a rocksalt oxide film on GaAsA single-crystalline MgO film was grown on GaAs (001) by constructing a complex heterostructure with two alkali halide buffer layers. The growth temperature was decreased to 150℃ as compared with direct growth of MgO on GaAs (001). Electron energy loss spectrum of the grown film agreed well with that of bulk MgO, indicating that surface stoichiometry was maintained. The structure was stable up to 600℃ against heating in, UHV condition. The concept of a complex heterostructure will help fabrication of functional oxide layers on GaAs substrates and lead to oxide/semiconductor integrated devices.(2) Epitaxial growth and phase transition of liqui … More d crystal monolayersMonolayer films of liquid crystals on single-crystalline inorganic substrates are expected to reveal novel properties involving phase transitions in two dimensions. It was found that liquid crystal 12CB can be grown epitaxially on alkali halide (OO1) surfaces. Temperature dependence of the film structure was investigated by using high-sensitive reflection high energy electron diffraction and atomic force microscopy. The shape of the monolayer boundary drastically changes with the substrate temperature near the transition temperature of 12CB.(3) Selective growth of molecular materials for quantum structuresSelective growth is the only practical method to fabricate well-defined nanostructures of molecular materials in large scales. Difference in the stabilization energies at film-substrate interfaces is essential to achieve high selectivity. Two guiding principles have been established. One is the use of lattice matching of the grown film and the substrate materials which is found among ionic substrate materials. The other is the use of different van der Waals interaction which is found using layered materials.(4) Physical properties of ultrathin films and heterostructuresPhysical properties of fabricated structures were measured and novel properties are being revealed. For example, MnPc ultrathin film shows magnetic properties different from bulk single crystals due to different molecular arrangement. Less