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Atomic force microscopy investigation of the kinetic growth mechanisms of sputtered nanostructured Au film on mica: towards a nanoscale morphology control.

Ruffino F, Torrisi V, Marletta G, Grimaldi MG - Nanoscale Res Lett (2011)

Bottom Line: Furthermore, we observed that the late stage of cluster growth is accompanied by the formation of circular depletion zones around the largest clusters.From the quantification of the evolution of the size of these zones, the Au surface diffusion coefficient was evaluated in D(T) = [(7.42 × 10-13) ± (5.94 × 10-14) m2/s]exp(-(0.33±0.04) eVkT).As a consequence we acquired a methodology to control the morphological characteristics of the Au film simply controlling the annealing temperature and time.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory for Molecular Surface and Nanotechnology (LAMSUN), Department of Chemical Sciences-University of Catania and CSGI, Viale A, Doria 6, 95125, Catania, Italy. vanna.torrisi@gmail.com.

ABSTRACT
The study of surface morphology of Au deposited on mica is crucial for the fabrication of flat Au films for applications in biological, electronic, and optical devices. The understanding of the growth mechanisms of Au on mica allows to tune the process parameters to obtain ultra-flat film as suitable platform for anchoring self-assembling monolayers, molecules, nanotubes, and nanoparticles. Furthermore, atomically flat Au substrates are ideal for imaging adsorbate layers using scanning probe microscopy techniques. The control of these mechanisms is a prerequisite for control of the film nano- and micro-structure to obtain materials with desired morphological properties. We report on an atomic force microscopy (AFM) study of the morphology evolution of Au film deposited on mica by room-temperature sputtering as a function of subsequent annealing processes. Starting from an Au continuous film on the mica substrate, the AFM technique allowed us to observe nucleation and growth of Au clusters when annealing process is performed in the 573-773 K temperature range and 900-3600 s time range. The evolution of the clusters size was quantified allowing us to evaluate the growth exponent 〈z〉 = 1.88 ± 0.06. Furthermore, we observed that the late stage of cluster growth is accompanied by the formation of circular depletion zones around the largest clusters. From the quantification of the evolution of the size of these zones, the Au surface diffusion coefficient was evaluated in D(T) = [(7.42 × 10-13) ± (5.94 × 10-14) m2/s]exp(-(0.33±0.04) eVkT). These quantitative data and their correlation with existing theoretical models elucidate the kinetic growth mechanisms of the sputtered Au on mica. As a consequence we acquired a methodology to control the morphological characteristics of the Au film simply controlling the annealing temperature and time.

No MeSH data available.


Related in: MedlinePlus

AFM images of the starting Au film: (a) 40 μm × 40 μm AFM scan of the starting 28-nm Au film sputter-deposited on the mica substrate; (b) 0.5 μm × 0.5 μm AFM scan of the same sample, to evidence the percolative nature of the film.
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Figure 1: AFM images of the starting Au film: (a) 40 μm × 40 μm AFM scan of the starting 28-nm Au film sputter-deposited on the mica substrate; (b) 0.5 μm × 0.5 μm AFM scan of the same sample, to evidence the percolative nature of the film.

Mentions: Figure 1a shows a 40 μm × 40 μm AFM image of the starting 28 nm Au film. We can observe that over such a scan size the Au film is very flat presenting a roughness σ = 1.2 nm. The roughness was evaluated using the SPMLabAnalyses V7.00 software: it is defined by where N is the number of data points of the profile, yi are the data points that describe the relative vertical height of the surface, and is the mean height of the surface. Furthermore, the roughness value was obtained averaging the values obtained over three different images.


Atomic force microscopy investigation of the kinetic growth mechanisms of sputtered nanostructured Au film on mica: towards a nanoscale morphology control.

Ruffino F, Torrisi V, Marletta G, Grimaldi MG - Nanoscale Res Lett (2011)

AFM images of the starting Au film: (a) 40 μm × 40 μm AFM scan of the starting 28-nm Au film sputter-deposited on the mica substrate; (b) 0.5 μm × 0.5 μm AFM scan of the same sample, to evidence the percolative nature of the film.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211157&req=5

Figure 1: AFM images of the starting Au film: (a) 40 μm × 40 μm AFM scan of the starting 28-nm Au film sputter-deposited on the mica substrate; (b) 0.5 μm × 0.5 μm AFM scan of the same sample, to evidence the percolative nature of the film.
Mentions: Figure 1a shows a 40 μm × 40 μm AFM image of the starting 28 nm Au film. We can observe that over such a scan size the Au film is very flat presenting a roughness σ = 1.2 nm. The roughness was evaluated using the SPMLabAnalyses V7.00 software: it is defined by where N is the number of data points of the profile, yi are the data points that describe the relative vertical height of the surface, and is the mean height of the surface. Furthermore, the roughness value was obtained averaging the values obtained over three different images.

Bottom Line: Furthermore, we observed that the late stage of cluster growth is accompanied by the formation of circular depletion zones around the largest clusters.From the quantification of the evolution of the size of these zones, the Au surface diffusion coefficient was evaluated in D(T) = [(7.42 × 10-13) ± (5.94 × 10-14) m2/s]exp(-(0.33±0.04) eVkT).As a consequence we acquired a methodology to control the morphological characteristics of the Au film simply controlling the annealing temperature and time.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory for Molecular Surface and Nanotechnology (LAMSUN), Department of Chemical Sciences-University of Catania and CSGI, Viale A, Doria 6, 95125, Catania, Italy. vanna.torrisi@gmail.com.

ABSTRACT
The study of surface morphology of Au deposited on mica is crucial for the fabrication of flat Au films for applications in biological, electronic, and optical devices. The understanding of the growth mechanisms of Au on mica allows to tune the process parameters to obtain ultra-flat film as suitable platform for anchoring self-assembling monolayers, molecules, nanotubes, and nanoparticles. Furthermore, atomically flat Au substrates are ideal for imaging adsorbate layers using scanning probe microscopy techniques. The control of these mechanisms is a prerequisite for control of the film nano- and micro-structure to obtain materials with desired morphological properties. We report on an atomic force microscopy (AFM) study of the morphology evolution of Au film deposited on mica by room-temperature sputtering as a function of subsequent annealing processes. Starting from an Au continuous film on the mica substrate, the AFM technique allowed us to observe nucleation and growth of Au clusters when annealing process is performed in the 573-773 K temperature range and 900-3600 s time range. The evolution of the clusters size was quantified allowing us to evaluate the growth exponent 〈z〉 = 1.88 ± 0.06. Furthermore, we observed that the late stage of cluster growth is accompanied by the formation of circular depletion zones around the largest clusters. From the quantification of the evolution of the size of these zones, the Au surface diffusion coefficient was evaluated in D(T) = [(7.42 × 10-13) ± (5.94 × 10-14) m2/s]exp(-(0.33±0.04) eVkT). These quantitative data and their correlation with existing theoretical models elucidate the kinetic growth mechanisms of the sputtered Au on mica. As a consequence we acquired a methodology to control the morphological characteristics of the Au film simply controlling the annealing temperature and time.

No MeSH data available.


Related in: MedlinePlus