An experimental study of Zirconium oxides

A. GOMEZ SANCHEZ; G. S. DUFFÓ; J. MENGHINI; G. BERNARDI; S. SUAREZ

Itapema

Conferencia; 20th International Conference on Ion Beam Analysis; 2011

International Atomic Energy Agency (IAEA)

The zirconium and its alloys have been studied in the past two decades with increasing interest due to their biomedical applications. The fundamental characteristic, however, for this behavior is the thin oxide biocompatible layer, which develop on contact with air or, artificially, with oxygenated electrolytes. This thin oxide film has the ability to decrease the amount of metallic ions towards the living tissue, facilitating the compatibility with metallic stent (osseointegration) [1] and reducing drastically the corrosion rate. This property allows us to imagine stents or metallic implants for orthopedic surgery with Zirconium or other material of low toxicity in which a layer of zirconium oxide can be attached or grown. The more or less oxide adhesion to the substrate material probably depends on the method used to grow the oxide, the physical and chemical conditions, and the substrate itself. In this work, we present in first place preliminary studies of zirconium oxides produced by anodization of zirconium metal. The oxide thickness, proportional to the anodization potential, is measured by electrochemical impedance spectroscopy (EIS) [2] and compared with results obtained with the technique of Rutherford backscattering (RBS). The homogeneity of the oxide surface was studied by atomic force (AFM) and scanning electron (SEM) microscopy. It appears that the oxide thickness for each anodizing potential is not uniform due to the growth of oxide in the form of islands. Secondly, we try the growth of zirconium oxide on a crystalline substrate of Silicon. The thickness and structure, crystalline or amorphous, were analyzed by X-ray techniques. We determined later the stopping power of alpha particles and the results were used to discuss differences with published data [3]. [1] D. Kohn, ?Metals in Medical Applications?, Current opinion in solid state & material science Vol.3 (1998), p.309-316. [2] E. Barsoukov, J.R. Macdonald editors, ?Impedance Spectroscopy. Theory, experiments and applicarions?, John Wiley & sons, Inc. New Jersey 2005. [3] M. Behar et al., Eur. Phys. J. D (2010) 164-168