title: Nanostructured arrays of semiconducting octahedral molecular sieves by pulsed-laser deposition.
abstract: Cryptomelane-type manganese oxide (OMS-2) has been widely used to explore the semiconducting and catalytic properties of molecular sieves with mixed-valent frameworks. Selective synthesis of patterned thin films of OMS-2 with hierarchical nanostructures and oriented crystals is challenging owing to difficulties in preserving the mixed valence, porosity and crystalline phase. Here, we report that pulsed-laser ablation of OMS-2 in an oxygen-rich medium produces a three-dimensional nanostructured array of parallel and inclined OMS-2 fibres on bare substrates of (001) single-crystal strontium titanate. Both parallel and inclined OMS-2 fibres elongate along the [001](OMS-2) direction. The parallel fibres interact strongly with the substrate and grow epitaxially along <110>(STO) with lattice misfits of less than 4%, whereas the inclined fibres are oriented with (301) parallel to the substrate surface. The spontaneous orientation of the crystalline OMS-2 domains over the STO surface opens up a new avenue in lattice-engineered synthesis of multilayer materials.
authors.affiliation: Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269-3136, USA.
authors.forename: Anais E
authors.initials: AE
authors.lastname: Espinal
authors.forename: Lichun
authors.initials: L
authors.lastname: Zhang
authors.forename: Chun-Hu
authors.initials: CH
authors.lastname: Chen
authors.forename: Aimee
authors.initials: A
authors.lastname: Morey
authors.forename: Yuefeng
authors.initials: Y
authors.lastname: Nie
authors.forename: Laura
authors.initials: L
authors.lastname: Espinal
authors.forename: Barrett O
authors.initials: BO
authors.lastname: Wells
authors.forename: Raymond
authors.initials: R
authors.lastname: Joesten
authors.forename: Mark
authors.initials: M
authors.lastname: Aindow
authors.forename: Steven L
authors.initials: SL
authors.lastname: Suib