In recent years, there has been great interest in self-organized pattern systems, such as patterned structures of wellaligned rods embedded in a matrix. These systems have been important in many research fields since Turing [1] mathematically demonstrated that such pattern formation in reactiondiffusion systems could account for morphogenesis. Some examples are: the fish-skin textures seen in mathematical biology, [2] concentration patterns like the Belousov-Zhabotinsky reaction in chemical systems, [3] and the phase separation seen during the directional solidification of some inorganic alloy substances.[4] These patterns are created in nonlinear open systems with a diffusion factor, where substance injection and ejection are allowed. Well-aligned structures of phase-separated inorganic materials are particularly attractive for use in new devices and processes. Such materials can be classified into two systems: 1) one-directional solidification into bulk and 2) film growth in vacuum. These are nonlinear open systems as they accompany injection caused by melting or depositing substances, and accompany ejection caused by freezing substances in a plane of solidification. Various well-aligned structures with a micrometer scale like the NiAl-Mo, [5] NaCl-LiF, [6] MgO-CaF 2 , [7] and EuB 6 -ZrB 2 [8] systems have been created by using a one-directional solidification method. However, it is difficult to obtain nanometerscale structures in bulk systems by using this method. Film-growth methods have provided a successful means for synthesizing well-aligned nanometer-scale structures, which are sometimes smaller than that achievable by using lithography techniques. Fe-LaSrFeO 4 , [9] BaTiO 3 -CoFe 2 O 4 , [10] AlSi, [11,12] and Al-Ge [13] systems have already been examined by using conventional physical vapor-deposition (PVD) methods. These deposited films also consist of two phases. One phase forms well-aligned rods normal to the substrate and another phase forms a matrix. Because of the interaction of these two phases, new effects are expected in these nanometer-scale phase-separated materials. In addition, several silicides have been investigated as material candidates for next-generation semiconductor devices. [14] These silicides can create Schottky-barrier and p-n junctions with silicon or other silicides. [14,15,16] It has been reported that iron disilicide, in particular, has an absorption coefficient almost 100 times higher than silicon in the near-infrared region. [17] This indicates that these are promising materials for near-infrared detector devices. Our concept is to fuse the physical properties in each phase of the nanometer-scale phase-separated structures to create new detector devices and to display quantum effects from the interaction of each phase. If a narrow distribution of diameters and spacing of rods in these phase-separated films could be achieved, their physical properties would also be well-defined with low dispersion. In this Communication, we report the well-aligned structure formation in var...

No abstract

No abstract

No abstract