Orientation symmetry breaking in self-assembled Ce1- : XGdxO2- y nanowires derived from chemical solutions
Queraltó López, Albert (Institut de Ciència de Materials de Barcelona)
De La Mata, Maria (Institut Català de Nanociència i Nanotecnologia)
Martínez, Lidia (Instituto de Ciencia de Materiales de Madrid)
Magen Dominguez, Cesar (Universidad de Zaragoza. Instituto de Nanociencia y Materiales de Aragón)
Gibert, Marta (Université de Genève. Département de Physique de la Matière Quantique)
Arbiol i Cobos, Jordi (Institut Català de Nanociència i Nanotecnologia)
Hühne, Ruben (Institut für Metallische Werkstoffe)
Obradors, Xavier (Institut de Ciència de Materials de Barcelona)
Puig i Molina, Mª Teresa (Institut de Ciència de Materials de Barcelona)

Data:	2016
Resum:	Understanding the growth mechanisms of nanostructures obtained from chemical solutions, a high-throughput production methodology, is essential to correlate precisely the growth conditions with the nanostructures' morphology, dimensions and orientation. It is shown that self-organized (011)-oriented Ce₀. ₉Gd₀. ₁O₂ᵧ (CGO) nanowires having a single in-plane orientation are achieved when an anisotropic (011)-LaAlO₃ (LAO) substrate is chosen. STEM and AFM images of the epitaxial nanowires reveal the (001)CGO[0-11](011)LAO[100] growth orientation, with the enlargement occurring along the [0-11]CGO direction with (111) lateral facets. The chosen substrate allowed us to study a unique case where the resulting biaxial strain is isotropic, while the dissimilar lateral surface energies are the key factor to obtain an energetically imbalanced and non-degenerated nanowire configuration. Rapid Thermal Annealing (RTA) has allowed sorting of experimental nucleation from coarsening and analysis of the kinetic phenomena of the nanowires. A thermodynamic driving force is shown to exist for a continuous elongation of the nanowires while the coarsening rates are found to be strongly temperature dependent and so kinetic effects are the key factors to control the size and density of the self-organized nanowire system. A remarkably fast nanowire growth rate (14-40 nm min⁻¹) is observed, which we associate with a high atomic mobility probably linked to a high concentration of oxygen vacancies, as detected by XPS. These nanowires are envisaged as model systems pushing forward the study of low energetic and highly oxygen deficient {111} lateral facets useful for catalysis, gas sensors and ionic conductivity applications.
Ajuts:	Ministerio de Economía y Competitividad SEV-2015-0496 Ministerio de Economía y Competitividad MAT2015-68994-REDC Ministerio de Economía y Competitividad MAT2014-51778-C2-1-R Ministerio de Economía y Competitividad ENE2014-56109-C3-3-R Ministerio de Economía y Competitividad SEV-2013-0295 Ministerio de Economía y Competitividad MAT2011-28874-C02-01 Ministerio de Economía y Competitividad CSD2007-00041 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-1638 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-753
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Matèria:	Chemical solutions ; Growth mechanisms ; Growth orientations ; In-plane orientation ; Rapid thermal annealing (RTA) ; Symmetry-breaking ; Temperature dependent ; Thermodynamic driving forces
Publicat a:	RSC advances, Vol. 6, issue 99 (2016) , p. 97226-97236, ISSN 2046-2069

DOI: 10.1039/c6ra23717g

Postprint 12 p, 1.9 MB

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