Comparison of lanthanum substituted bismuth titanate (BLT) thin films deposited by sputtering and pulsed laser deposition

Autor: Marie-Paule Besland, Mohamed Abdou Djouadi, P. Y. Tessier, S. Lafane, P.R.J. Barroy, Luc Brohan, B. Angleraud, H. Djani-ait Aissa, Mireille Richard-Plouet
Přispěvatelé: Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)
Jazyk: angličtina
Rok vydání: 2006
Předmět:
Zdroj: Thin Solid Films
Thin Solid Films, Elsevier, 2006, 495, pp.86. ⟨10.1016/j.tsf.2005.08.154⟩
ISSN: 0040-6090
DOI: 10.1016/j.tsf.2005.08.154⟩
Popis: Bi 4− x La x Ti 3 O 12 (BLT x ), ( x = 0 to 1) thin films were grown on silicon (100) and platinized substrates Pt/TiO 2 /SiO 2 /Si using RF diode sputtering, magnetron sputtering and pulsed laser deposition (PLD). Stoichiometric home-synthesized targets were used. Reactive sputtering was investigated in argon/oxygen gas mixture, with a pressure ranging from 0.33 to 10 Pa without heating the substrate. PLD was investigated in pure oxygen, at a chamber pressure of 20 Pa for a substrate temperature of 400–440 °C. Comparative structural, chemical, optical and morphological characterizations of BLT thin films have been performed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Spectro-ellipsometric measurements (SE) and Atomic Force Microscopy (AFM). Both sputtering techniques allow to obtain uniform films with thickness ranging from 200 to 1000 nm and chemical composition varying from (Bi,La) 2 Ti 3 O 12 to (Bi,La) 4.5 Ti 3 O 12 , depending on deposition pressure and RF power. In addition, BLT films deposited by magnetron sputtering, at a pressure deposition ranging from 1.1 to 5 Pa, were well-crystallized after a post-deposition annealing at 650 °C in oxygen. They exhibit a refractive index and optical band gap of 2.7 and 3.15 eV, respectively. Regarding PLD, single phase and well-crystallized, 100–200 nm thick BLT films with a stoichiometric (Bi,La) 4 Ti 3 O 12 chemical composition were obtained, exhibiting in addition a preferential orientation along (200). It is worth noting that BLT films deposited by magnetron sputtering are as well-crystallized than PLD ones.
Databáze: OpenAIRE