電子照射によるコバルトホウ化物のアモルファス化

抄録

The electron irradiation-induced crystalline to amorphous (C-A) transition in the Co-B binary system was examined by ultra-high voltage electron microscopy. The five equilibrium phases (i.e., Co, Co₃B, Co₂B, CoB, and B) in the system were irradiated with 2 MeV electrons at a fixed temperature of approximately 110K, and the tendency towards the amorphization was compared. Of the five, only Co₃B and Co₂B underwent a C-A transition by the irradiation while the other three remained crystalline. The tendency towards the amorphization under electron irradiation is best correlated with the position of the materials in the corresponding temperature-composition phase diagram; those compounds located near the bottom of the deep valleys of the liquidus in the diagram are rendered amorphous, while those which are located away from such valleys do not exhibit the C-A transition.