Gries, Thomas , Catrin, Rodolphe , Migot, Sylvie , Soldera, Flavio , ENDRINO ARMENTEROS, JOSÉ LUIS, Landa-Canovas, Angel R. , Cleymand, Franck , Mangin, Denis , Muecklich, Frank , Horwat, David
Si
ACS Appl. Mater. Interfaces
Article
Científica
6.723
2.125
27/08/2014
000341122000049
2-s2.0-84906810067
Nanocomposite films consisting of gold nano-particles embedded in an yttria-stabilized zirconia matrix (Au-YSZ) have been synthesized with different gold loadings by reactive magnetron sputtering followed by ex situ annealing in air or laser interference patterning (LIP) treatment. It is shown that the electrical conductivity of the nanocomposite films can be modified to a large extent by changing the gold loading, by thermal annealing, or by LIP. The structural and microstructural analyses evidenced the segregation of metallic gold in crystalline form for all synthesis conditions and treatments applied. Thermal annealing above 400 degrees C is observed to trigger the growth of pre-existing nanoparticles in the volume of the films. Moreover, pronounced segregation of gold to the film surface is observed for Au/(Au + Zr + Y) ratios above 0.40, which may prevent the use of thermal annealing to functionalize gold-rich Au-YSZ coatings. In contrast, significant modifications of the microstructure were detected within the interference spot (spot size close to 2 x 2 mm) of LIP treatments only for the regions corresponding to constructive interference. As a consequence, besides its already demonstrated ability to modify the friction behavior of Au-YSZ films, the LIP treatment enables local tailoring of their electrical resistivity. The combination of these characteristics can be of great interest for sliding electrical contacts.
nanocomposite films; electrical conductivity; gold nanoparticles; laser interference patterning; thermal annealing; microstructure