title: Self assembly of nanoislands on YSZ-(001) surface: a mechanistic approach toward a robust process.
abstract: We experimentally investigate the mechanism of formation of self-assembled arrays of nanoislands surrounding dopant sources on the (001) surface of yttria-stabilized zirconia. Initially, we used lithographically defined thin-film patches of gadolinia-doped ceria (GDC) as dopant sources. During annealing at approximately one-half the melting temperature of zirconia, surface diffusion of dopants leads to the breakup of the surface around the source, creating arrays of epitaxial nanoislands with a characteristic size (~100 nm) and alignment along elastically compliant directions, <110>. The breakup relieves elastic strain energy at the expense of increasing surface energy. On the basis of understanding the mechanism of island formation, we introduce a simple and versatile powder-based doping process for spontaneous surface patterning. The new process bypasses lithography and conventional vapor-source doping, opening the door to spontaneous surface patterning of functional ceramics and other refractory materials. In addition to using GDC solid-solution powders, we demonstrate the effectiveness of the process in another system based on Eu2O3.
authors.affiliation: Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Haris M
authors.initials: HM
authors.lastname: Ansari
authors.forename: Vikas
authors.initials: V
authors.lastname: Dixit
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Zimmerman
authors.forename: Michael D
authors.initials: MD
authors.lastname: Rauscher
authors.forename: Suliman A
authors.initials: SA
authors.lastname: Dregia
authors.forename: Sheikh A
authors.initials: SA
authors.lastname: Akbar