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.