A New Approximant of the Decagonal Quasicrystal and Ultrafine Particles Intercepted and Captured under High Static Pressure

In this paper, we reported a new approximant of Al70Co15Ni10Tb5 decagonal quasi-crystal obtained by quenching from melting state (1 700 ℃) under high static pressure (7.0 GPa) for the first time. The approximant is a B-type orthorhombic crystalline phase and its lattice parameters are a=2.28 nm, b=1.6 nm, c=5.46 nm. A two-dimensional lattice model of the approximant is supposed by means of the high-resolution electron microscopy pattern. Besides, many ultrafine particles are found in this sample. They are spherical and their sizes are 30～40 nm.