Nanostructured arrays of semiconducting octahedral molecular sieves by pulsed-laser deposition.
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.
Espinal
Anais E
AE
Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269-3136, USA.
Zhang
Lichun
L
Chen
Chun-Hu
CH
Morey
Aimee
A
Nie
Yuefeng
Y
Espinal
Laura
L
Wells
Barrett O
BO
Joesten
Raymond
R
Aindow
Mark
M
Suib
Steven L
SL