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The main objective of this work is the preparation of decorative zirconium oxynitride, ZrOxNy, thin films by dc reactive magnetron sputtering. Film properties were analyzed as a function of the reactive gas flow and were correlated with the observed structural changes. Measurements showed a systematic decrease in the deposition rate with the increase of the reactive gas flow and revealed three distinct modes: (i) a metallic mode, (ii) a transition mode (subdivided into three zones), and (iii) an oxide mode. The measurements of target potential were also consistent with these changes, revealing a systematic increase from 314to337V. Structural characterization uncovered different behaviors within each of the different zones, with a strong dependence of film texture on the oxygen content. These structural changes were also confirmed by resistivity measurements, whose values ranged from 250to400μΩcm for low gas flows and up to 106μΩcm for the highest flow rates. Color measurements in the films revealed a change from bright yellow at low reactive gas flows to red brownish at intermediate flows and dark blue for the films prepared at the highest flows. Hardness measurements gave higher values for the region where larger grain sizes were found, showing that the grain growth hardening effect is one of the main parameters that can help explain the observed behavior. Also the peak intensity ratio and the residual stress states were found to be important factors for explaining this behavior.

The main purpose of this work consists on the preparation of single layered zirconium oxynitride, ZrN x O y , thin films, deposited by rf reactive magnetron sputtering. The depositions were carried out by varying the process parameters such as substrate bias voltage and flow rate of the reactive gases. Independently of O content, the samples prepared with oxygen fractions revealed crystalline structures basically constituted by face centred cubic ZrN grains. Atomic force microscopy (AFM) observation showed lower values of surface roughness for low oxygen fractions and a second region where roughness grows significantly, corresponding to the highest oxygen fractions. Ion bombardment promoted a continuous smoothing of the surface up to a bias voltage of À66 V. At a bias voltage of À75 V, roughening is again observed. The small increase of film hardness in low oxygen fractions ZrN x O y films was attributed to lattice distortions occurring as a result of the possible oxygen incorporation within the ZrN lattice and also grain size reduction. Residual stresses appeared to be an important parameter to explain the observed behaviour, namely in the group of samples prepared with variation in the bias voltage. Regarding colour variations, it was observed a clear dependence of the obtained colorations with oxygen fraction.

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This paper reports on the preparation of TiN x thin films by d.c. reactive magnetron sputtering. The coating thickness ranged from 1.7 to 4.2 Am and the nitrogen content varied between 0 and 55 at.%. X-Ray diffraction showed the development of the hexagonal a-Ti phase, with strong [002] orientation for low nitrogen contents, where the N atoms fit into octahedral sites in the Ti lattice as the amount of nitrogen is increased. For nitrogen contents of 20 and 30 at.%, the q-Ti 2 N phase appears with [200] orientation. With further increasing the nitrogen content, the y-TiN phase becomes dominant. The electrical resistivity of the different compositions reproduces this phase behavior. The hardness of the samples varied from approximately 8 GPa for pure titanium up to 27 GPa for a nitrogen content of 30 at.%, followed by a slight decrease at the highest contents. A similar increase of stresses with nitrogen is observed. Structure and composition with the consequent changes in crystalline phases and the lattice distortion were found to be crucial in the evolution of the mechanical properties.

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