1. Introduction
Special zirconium-based multi-component alloys posses a high glass-forming ability making the preparation of bulk amorphous samples possible which show in particular very interesting mechanical properties, i.e. very high strength [1]. However, potential applications also depend on the environ- mental stability of these alloys [2]. Their corrosion behavior is mainly characterized by electrochemical methods. In a wide pH-value range amorphous Zr– Cu–Ni–Al–[Ti, Nb] alloys exhibit an excellent anodic passivation behavior, which is attributed to the formation of barrier-type thin oxide films by a high- field controlled growth mechanism [3,4].
Surface analytical methods (Auger electron spec- troscopy (AES), XPS) can provide information about the nature and thickness of films formed during electrochemical treatment. These methods apply sputter depth profiling, which can result in preferential sputtering [5].
In this work, the composition of oxide layers formed on a series of amorphous Zr alloys was studied. Their nominal compositions are given in Table 1. It was verified by atomic absorption pectrometry that the compositions of the ribbons after two-step casting correspond to the nominal data within a deviation limit of