Nanocrystalline Ferroelectric BiFeO3 Thin Films by Low-Temperature Atomic Layer Deposition

© 2015 American Chemical Society. In this work, ferroelectricity is identified in nanocrystalline BiFeO<inf>3</inf> (BFO) thin films prepared by low-temperature atomic layer deposition. A combination of X-ray diffraction, reflection high energy electron diffraction, and scanning transmis...

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Bibliographic Details
Authors: Coll, Mariona, Gázquez, Jaume, Fina, Ignasi, Khayat, Zakariya, Quindeau, Andy, Alexe, Marin, Varela, María, Trolier-McKinstry, Susan, Obradors, Xavier, Puig Molina, Teresa
Format: article
Status:Versión aceptada para publicación
Publication Date:2015
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/136432
Online Access:http://hdl.handle.net/10261/136432
Access Level:Open access
Keyword:Ferroelectric perovskite
Atomic layer deposition
Thin film
BiFeO3
Description
Summary:© 2015 American Chemical Society. In this work, ferroelectricity is identified in nanocrystalline BiFeO<inf>3</inf> (BFO) thin films prepared by low-temperature atomic layer deposition. A combination of X-ray diffraction, reflection high energy electron diffraction, and scanning transmission electron microscopy analysis indicates that the as-deposited films (250 °C) consist of BFO nanocrystals embedded in an amorphous matrix. Postannealing at 650 °C for 60 min converts the sample to a crystalline film on a SrTiO<inf>3</inf> substrate. Piezoelectric force microscopy demonstrates the existence of ferroelectricity in both as-deposited and postannealed films. The ferroelectric behavior in the as-deposited stage is attributed to the presence of nanocrystals. Finally, a band gap of 2.7 eV was measured by spectroscopic ellipsometry. This study opens broad possibilities toward ferroelectric oxides on 3D substrates and also for the development of new ferroelectric perovskites prepared at low temperature.