X-ray combined analysis of fiber-textured and epitaxial Ba(Sr,Ti)O3 thin films deposited by radio frequency sputtering

Abstract

A complete study is given in this paper on the structural properties of Ba(Sr,Ti)O3 (BST) thin films which present various preferred orientations: (111) and (001) fiber and epitaxial textures. The films are deposited in situ at 800 °C by sputtering on Si/SiO2/TiOx/Pt substrates and the orientation is controlled by monitoring the concentration of O2 in the reactive plasma or by prior deposition of a very thin TiOx buffer layer between BST films and substrates. The epitaxial films are obtained on (001)-alpha-Al2O3 substrates covered with TiOx buffer layers. In order to analyze finely the preferred orientations, the texture, the microstructural features, and the anisotropy-related quantities such as residual stresses in the films, the conventional Bragg−Brentano θ - 2θ x-ray diffraction diagrams is shown not to be sufficient. So, we systematically used x-ray combined analysis, a recently developed methodology which gives access to precise determination of the structure (cell parameters and space group) of the films, their orientation distributions (texture strengths and types) and mean crystallite sizes, their residual stresses. This fine structural analysis shows important modifications between the film qualities which induce differences in BST films electrical behavior, permittivity, loss tangent, and tunability.

Structural and multiferroic properties of Fe-doped Ba0.5Sr0.5TiO3 solids

“…Previous studies mainly focused on BST thin films. Many film growth techniques have been employed to prepare BST thin films, such as metalorganic vapor phase epitaxy [15], sputtering [16], molecular beam epitaxy [17,18], pulsed laser deposition [19], and soft solution processing [20]. BST has been mainly used for dielectric devices such as capacitors for dynamic random access memory because of its high dielectric constant and low dissipation factor [21][22][23][24][25].…”

Fast pole figure acquisition using area detectors at the DiffAbs beamline – Synchrotron SOLEIL

“…The texture of a crystalline sample can be described as the preferred orientation of its crystallites (Cullity, 1978) and can vary from simple (e.g. random, fibrelike; Pellegrino et al, 2012;Remiens et al, 2011;Fei et al, 2009;Beckers et al, 2010;Deniz & Harper, 2008), to epitaxial (Remiens et al, 2011;Dong et al, 2001;Ö zcan et al, 2002;Barbier et al, 2007;Mocuta et al, 2003), to rather complex (e.g. axiotaxy; Detavernier et al, 2003;Detavernier & Lavoie, 2004).…”

Ferroelectric and Dielectric Properties of Strontium Titanate Doped with Barium

“…The extension of (Sr) into BaTiO 3 changes the Curie point to make BST a paraelectric material at room temperature, offering a high dielectric constant and low leakage current. Previous studies [6][7][8][9][10][11][12][13][14][15] have explained different techniques for obtaining BST.…”