アモルファス合金の化学的原子配列

抄録

Amorphous structure has been investigated from not only the topological viewpoint but also the chemical one. Especially, the neutron diffraction allows one to observe directly the concentration-concentration correlation functions of the neutron zero scattering amorphous alloys. The chemical short-range order (CSRO) of Ti-Cu and Ti-Ni neutron zero scattering amorphous alloys differs from each other, even though Ni, being located next to Cu in the Periodic Table, has an atomic size which is almost the same as that of Cu. The CSRO of Ti-Ni-Cu ternary neutron zero-scattering amorphous alloys is found to increase rapidly with increasing Ni content. The results indicate that an increase of the CSRO by alloying with Ni element is ascribed to the stronger affinity of a Ni atom with a Ti atom than that of a Cu atom. Moreover, the CSRO strongly affects with the thermal properties, i.e., the crystallization temperature and the enthalpy of crystallization.