1999 年 41 巻 2 号 p. 141-145
We have synthesized a twelvefold quasicrystal Ta62Te38 by non-equilibrium solid state reactions. A transmission electron microscopy study reveals that the so-called twelvefold quasicrystal Ta62Te38 is a crystal subjected to the structure modulation. It is composed of two incommensurate layers rotated by 30° (or 90°) to each other about their normal. High resolution electron microscope images show the formation of commensurate domains and their discommensuration. The modulation is considered to be due to the rearrangement of atomic vacancies as a response to the occurrence of charge density waves.