Anelastic Relaxations of La-based Amorphous Alloys

The relaxation processes of La-based amorphous alloys with distinct glass transition phenomenon have been investigated in the temperature regions around the glass transition temperature and well below the glass transition temperature by the dynamic mechanical measurements. The amorphous alloys used in this study are La_Al_Ni_x (x=0 to 35 %) and La_5Al_Ni_ alloys for examination of the compositional effect and La_Al_M_ (M=Cu, Pd or Au) alloys for the substitutional effect. The sub-T_g relaxation phenomenon was observed for La_Al_Ni_x (x=5 to 35 %) and La_5Al_Ni_ amorphous alloys. The relaxation due to the glass transition was recognized for La_Al_Ni_x (x=0 to 35 %), La_5Al_Ni_ and La_Al_M_ (M=Cu, Pd or Au) amorphous alloys. In addition, the second-stage relaxation in the glass transition region was also observed for La_Al_Ni_x (x=15 to 30 %) and La_Al_M_ (M=Cu, Pd or Au) amorphous alloys with a wide supercooled liquid region exceeding 35 K. The appearance of the two kinds of relaxation units seems to reflect the difference in the chemical bonding nature among the constituent elements