Kenji Yasui

Synthesis of Well-Aligned Diamond Nanocylinders**

By Hideki Masuda,* Takashi Yanagishita, Kenji Yasui,Kazuyuki Nishio, Ichizo Yagi, Tata N. Rao, andAkira FujishimaDiamond and related materials have attracted intense inter-est because of several outstanding properties including nega-tive electron affinity (NEA) and high stability. These materi-als are expected to be promising for cold-cathode flat-panelelectronic displays and microelectronics.

Ideally Ordered Anodic Porous Alumina Mask Prepared by Imprinting of Vacuum-Evaporated Al on Si.

Application of imprinting of vacuum-evaporated Al on a Si substrate using an SiC mold with an ordered array of hexagonally arranged convexes and subsequent anodization yielded an ideally ordered porous alumina mask on the substrate. The obtained alumina mask has sufficient adhesion to a Si substrate, and was used as a mask for vacuum evaporation of metal and ion milling of the Si substrate.

Patterned magnetic recording media using anodic porous alumina with single domain hole configurations of 63 nm hole interval

Patterned magnetic recording media composed of the arrays of Co cylinders were fabricated using anodic porous alumina with single domain hole configuration. The ac electrodeposition of Co into the holes of the alumina matrix of 63 nm hole interval generated the arrays of Co cylinders with high aspect ratios. The structures and magnetic properties of the obtained patterned magnetic recording media are described. The magnetic recording properties were dependent on the geometrical structures of the Co cylinder arrays in the alumina matrix.

Fabrication of nanocomposites by filling nanoholes in highly ordered anodic porous alumina by vacuum deposition of metal

Nanocomposite structures of a metal and an alumina matrix were prepared by depositing a metal into holes in anodic porous alumina using vacuum deposition. The process, which was composed of sequences of metal deposition into straight holes and then peeling of the deposit on the surface, induced an almost uniform filling of the holes that had aspect ratio of 4.

Direct Nanomolding of Semiconductor Single Crystals

An ordered array of concaves of nanometer-scale dimensions was fabricated by a direct molding process on an InP single crystal using a SiC master mold. The obtained array of concaves could be applied for the preparation of an ordered textured surface of InP by a post-etching treatment. The treatment in hydrofluoric acid (HF) solution generated a highly ordered and textured surface composed of uniform pyramidal or triangular pits. The mold could be used repeatedly, and this method enables simple maskless patterning of semiconductor single crystals.