Patterning Co nanoclusters on thin-filmAl2O3/NiAl(100)

Abstract

Self-organized patterning of supported nanoclusters by virtue of low cost andreadiness for mass production is considered as one of the most promisingmethods; however, this approach is challenging, since the capability of controllingthe patterns relies on a suitable combination of clusters and templates. In thispaper we demonstrate that Co nanoclusters grown from vapour deposition overAl2O3 thin films on NiAl(100) substrate make a perfect combination for self-organizedpatterning. Uniform and sizeable Co nanoclusters are formed only on crystallineAl2O3 films and they are highly aligned by protrusion structures of the crystallineAl2O3. Through simple thermal treatments we can pattern the crystallineAl2O3 films and consequently the grown Co nanoclusters. The patterns are robust as they aresustained even when the Co nanoclusters are flashed to 750 K, exposed to atmosphere orthe coverage is increased to coalescence. Moreover, the patterns can be further refined byusing STM tips. The results imply potential applications in both fundamental andapplied researches for electronic and magnetic nanodevices as well as catalysis.