On the formation of an interface amorphous layer in nanostructured ferroelectric Ba0.8Sr0.2TiO3 thin films integrated on Pt-Si and its effect on the electrical properties

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Silva, JPB (Author) Other; Sekhar, KC (Author) Other; Rodrigues, SAS (Author) Other; Pereira, M (Author) Other; Parisini, A (Author) Other; Alves, E (Author) Other; Barradas, NP (Author) Other; Gomes, MJM (Author) Other

Journal

Title: Applied Surface Science

Vol. 278

Pages: 136-141

ISSN: 0169-4332

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 8 Citations

Other information

Authenticus ID: P-006-8VY

DOI: 10.1016/j.apsusc.2012.11.161

Abstract (EN): The thin films of Ba0.8Sr0.2TiO3 (BST) investigated in this work were produced by pulsed laser deposition at different pulse-repetition frequencies (PRFs). First measurements by X-ray diffraction suggested a crystalline nature of the deposited films. However, scanning transmission electron microscopy and transmission electron microscopy images have revealed that a BST amorphous layer of considerable thickness is formed at the interface between the film and the Pt layer in the films deposited at 10 Hz. Moreover, energy-dispersive X-ray spectroscopy shows that the composition of the BST layer is the same in both the amorphous and the crystalline phases whereas Rutherford backscattering spectrometry measurements have revealed a stoichiometry of the films identical to that of the target. A new interpretation is proposed to explain the formation of this amorphous layer, based on the PRF used during the deposition. Finally, measurements of dielectric and electric properties were performed on as-grown and annealed samples. The results of these measurements are explained by a model, where a low-permittivity amorphous layer is connected in series with the crystalline BST layer.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6