Abstract:X-ray diffraction and DSC were used to investigate the crystallization process of amorphous Al₉₀Fe₅Ce₅ and Al₉₀Ni₅Ce₅ alloys, and the stability of the structure corresponding to the prepeak. Both these amorphous alloys are crystallized by two stages. The stability of the structure corresponding to the prepeak has a large difference. The structure corresponding to the prepeak for amorphous Al₉₀Fe₅Ce₅ alloy is more stable than the amorphous matrix. However, it is not stable for amorphous Al₉₀Ni₅Ce₅ alloys during the first crystallization stage. The prepeak position of amorphous Al₉₀Ni₅Ce₅ alloys is very close to that of amorphous Al₉₀Fe₅Ce₅ alloys. It is estimated that the prepeak is also due to diffraction peak broadening caused by very fine quasi-crystalline structure and the structural unit is an icosahedral quasi-crystalline structure with Ni as the central atom. The large difference of the stability of the structure corresponding to the prepeak is likely caused by different stability of the quasi-crystalline structure.

Key words:   amorphous Al₉₀TM₅Ce₅ alloy; prepeak; stability; crystallization