Fabrication of their properties

该项目旨在建立在从无机到无机、从绝缘体到超导体的各种材料中制造高度非均质晶体结构所必需的技术。从这些奇特的结构中发现了新的物理性质。(1)在GaAs（001）上构建具有两层碱卤化物缓冲层的复杂异质结构，在GaAs（001）上生长出具有岩盐氧化物膜的单晶MgO膜。与在GaAs上直接生长相比，MgO的生长温度降低到150℃（001）。生长膜的电子能量损失谱与体MgO的电子能量损失谱吻合较好，表明表面化学计量保持不变。在超高压条件下，该结构在高达600℃的高温下保持稳定。复杂异质结构的概念将有助于在GaAs衬底上制造功能氧化物层，并导致氧化物/半导体集成器件。(2)液晶的外延生长和相变更多的单晶单层液晶膜在单晶无机衬底上的单层液晶膜有望揭示涉及二维相变的新特性。发现12CB液晶可以在碱卤化物（OO1）表面外延生长。利用高灵敏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12CB的转变温度附近，随着衬底温度的升高，单层边界的形状发生了剧烈的变化。(3)分子材料量子结构的选择性生长选择性生长是制备分子材料纳米结构的唯一可行方法。薄膜-衬底界面稳定能的差异是实现高选择性的必要条件。已经确立了两项指导原则。一种是利用生长薄膜和衬底材料的晶格匹配，这种匹配在离子衬底材料中发现。另一个是使用不同的范德华相互作用，这是使用分层材料发现的。(4)超薄膜和异质结构的物理性质测量了制备结构的物理性质，揭示了新的性质。例如，由于分子排列的不同，MnPc超薄膜表现出不同于块状单晶的磁性能。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