The structure of rapidly solidified Ge-Al-La alloys, as investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM), is discussed in comparison with that of Al-Ge-TM (TM = transition metals) alloys. Rapidly solidified Ge-Al-La alloys, being metastable materials, transform into an equilibrium state upon heating. Phase transformations in the above-mentioned alloys were studied by differential scanning and isothermal calorimetry. (C) 2000 Elsevier Science Ltd.