Structure and crystallization behavior of Al-free Ge-based amorphous alloys produced by rapid solidification of the melt

Ge-based amorphous alloys produced by rapid solidification of the melt usually contain Al as one of the important alloying elements for improving their glass-forming ability. In the present paper we discuss the formation of two Ge-based amorphous alloys in Ge–Ni–La and Ge–Li–Ca systems, where Ge is alloyed with heavy Ni, La and light Li, Ca elements. The structure and crystallization behavior of the Ge–Ni–La alloy were extensively studied by transmission electron microscopy (TEM) including high-resolution imaging, differential scanning calorimetry (DSC) and X-ray diffractometry. The nature of phase transformations is discussed on the basis of isothermal and continuous heating data analyses as well as the results of in situ X-ray diffraction (XRD) studies during heating.