Enhanced metal nucleation with

Enhanced Metal Nucleation with Self-Assembled Monolayers of a -Substituted Silanes Studied by Scanning Force Microscopy... 

Coating substrates with a thin film of metals, such as Fe, Cu, Ti, Nb, Mo, or Ni, has been used to enhance diamond nucleation. 

Ni, and Zn on montmorillonite, Al-montmorillonite and Ali3-montmorillonite. Addition of Al enhanced metal sorption of Ni and Zn and sorption increased with time, while Pb and Cd sorption were not affected by addition of Al. This finding agrees with the results of a recent XAFS study with Pb in our laboratory. No nucleation products seem to occur with Pb at surface loadings on clay minerals and y-Al-oxide where nuclation products have been observed with smaller metals such as Co, Cu and Ni (Strawn, D. G., The University of Delaware, unpublished data). This sorption behaviour of Pb appears to be related to the mismatch in size between Pb (1.19A), and AP (0.54A) that is contained in the structure of the clay minerals and Al-oxide. The Pb ion is too large to fit into the mineral structure, while ions such as Ni (0.69A) and Co (0.75A) can fit into the structure (Table I). 

The H profile in the y direction supports the presence of an outer softer amorphous layer (H = 120 MPa) in the samples with Tmouid below 120 °C (Pig. 7.8). However, on increasing Tmouid above 120 °C, the amorphous layer crystallizes and hardens. It should be noted that for the samples prepared at Tmouid > 120 °C, H shows a distinct maximum value at both surfaces, suggesting an enhancing nucleation effect of the metallic walls of the mould on the crystallizing material. 

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