Heteroepitaxial growth of anatase (0 0 1) films on SrTiO3 (0 0 1) by PLD and MBE
Crespo Villanueva, Adrián (Institut de Ciència de Materials de Barcelona)
Gallenberger, Julia (Technische Universität Darmstadt)
De Santis, M. (Université Grenoble Alpes)
Langlais, Veronique (Centre d'Elaboration de Matériaux et Etudes Structurales)
Carla, Francesco (Diamond Light Source)
Caicedo Roque, Jose Manuel (Institut Català de Nanociència i Nanotecnologia)
Rius Palleiro, Jordi (Institut de Ciència de Materials de Barcelona)
Torrelles Albareda, Xavier (Institut de Ciència de Materials de Barcelona)

Date:	2023
Abstract:	The epitaxial growth of anatase (0 0 1) films deposited by pulsed laser deposition (PLD) and molecular beam epitaxy (MBE) on SrTiO (0 0 1) (STO) single crystals has been studied using X-ray diffraction and surface sensitivity UHV techniques. The evolution of the strain represented by the microstrain and the change of the in-plane and out-of-plane lattice parameters with film growth temperature, the effect of the annealing temperature and the influence of the oxygen content of the film have been investigated. The out-of-plane lattice strain shows a compressive (−0. 2 %) or expansive (+0. 3 %) behavior, in the range 600-900 °C, for temperatures below or above 700 °C, respectively. The in-plane lattice parameters, as well as the cell volume of the film, remain under compression over the entire temperature range explored. PLD films grow into square islands that align with the surface lattice directions of the STO substrate. The maximum size of these islands is reached at growth temperatures close to 875-925 °C. Film annealing at temperatures of 800 °C or higher melts the islands into flat terraces. Larger terraces are reached at high annealing temperatures of 925 °C for extended periods of 12 h. This procedure allows flat surface terrace sizes of up to 650 nm to be achieved. The crystalline quality achieved in anatase films prepared by PLD or MBE growth methods is similar. The two-step anatase growth process used during the synthesis of the films with both methods: film growth and post-annealing treatment in oxygen or air at ambient pressure, using temperature and time as key parameters, allows to control the surface terrace size and stoichiometry of the films, as well as the anatase/rutile intermixing rates at sufficiently high temperatures. This growth process could allow the substitution of their equivalent single crystals. The range of applicability of these films would include their use as structural and electronic model systems, or in harsh experimental conditions due to their low production cost.
Grants:	Ministerio de Ciencia e Innovación CEX2019-000917-S Ministerio de Ciencia e Innovación PID2021-123276OB-I00 Ministerio de Ciencia e Innovación CEX2021-001214-S
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Annealing temperatures ; Diffraction sensitivity ; Growth process ; Micro-strain ; Molecular-beam epitaxy ; Out-of-plane lattice parameters ; Pulsed-laser deposition ; Surface sensitivity ; Surface terraces ; X- ray diffractions
Published in:	Applied surface science, Vol. 632 (September 2023) , art. 157586, ISSN 0169-4332

DOI: 10.1016/j.apsusc.2023.157586

13 p, 10.3 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles