XRD and FTIR analysis of Ti–Si–C–ON coatings for biomedical applications

• Published in: Surface & coatings technology Vol. 203; no. 5; pp. 490 - 494
• Main Authors: Oliveira, Cristina, Gonçalves, L., Almeida, B.G., Tavares, C.J., Carvalho, S., Vaz, F., Escobar_Galindo, R., Henriques, M., Susano, M., Oliveira, R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 25.12.2008; Elsevier
• Subjects: Applied sciences; Biofilm formation; Corrosion; Corrosion environments; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; FTIR; Materials science; Metals. Metallurgy; Physics; Production techniques; Resistivity; Sputtering; Surface treatment; Surface treatments; Biofilm formation; FTIR; Resistivity; Sputtering; Electrical conductivity; Electrical properties; Biofilm; Surface treatments; Bacterial corrosion; Coatings; Medical application
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2008.06.121

Ti–Si–C–ON films were deposited by DC reactive magnetron sputtering using different partial pressure ratio of oxygen ( p O 2 ) and nitrogen ( p N 2 ). Compositional analysis revealed the existence of three different growth zones for the films; (I) N/Ti = 2.1 (high atomic ratio) and low oxygen content; (II) 0.76 < N/Ti < 2.1 (intermediate atomic ratio) and (III) N/Ti ≤ 0.12 (low ratio) and high oxygen content. For high N/Ti atomic ratio (N/Ti = 2.1) the XRD pattern exhibits reflections that correspond to a mixture of two different phases: a metallic-like Ti and a fcc NaCl type structure. Its electrical resistivity presents a metallic character and, consequently, has high infrared reflectivity. For the intermediate N/Ti ratio (0.76 < N/Ti < 2.1), the films crystallize in a B1-NaCl crystal structure typical for TiC 0.2N 0.8. Their FTIR spectra present C–N modes, besides the TiN ones, that indicate a progressive substitution of nitrogen by carbon atoms with increasing oxygen content (and lowering N/Ti ratio). For the highest oxygen content (and lower N/Ti ratio) the presence of the Ti–O–Ti stretching mode shows the formation of highly resistive Ti–O compounds consistent with the semiconductor character of this film. Biofilm formation as well as material cytotoxicity seemed to be related with the presence of the Ti.