1 research outputs found
Local Modification of the Microstructure and Electrical Properties of Multifunctional Au–YSZ Nanocomposite Thin Films by Laser Interference Patterning
Nanocomposite films consisting of
gold nanoparticles 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 °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 × 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