Electronic structures and abnormal phonon behaviors of cobalt-modified Na0.5Bi0.5TiO3-6%BaTiO3 single crystals

T. Huang; P. Zhang; L. P. Xu; C. Chen; J. Z. Zhang; Z. G. Hu; H. S. Luo; J. H. Chu

doi:10.1063/1.4966910

AIP Advances (Oct 2016)

Electronic structures and abnormal phonon behaviors of cobalt-modified Na0.5Bi0.5TiO3-6%BaTiO3 single crystals

T. Huang,
P. Zhang,
L. P. Xu,
C. Chen,
J. Z. Zhang,
Z. G. Hu,
H. S. Luo,
J. H. Chu

Affiliations

T. Huang: Technical Center for Multifunctional Magneto-Optical Spectroscopy (ECNU), Shanghai, China and Department of Electronic Engineering, East China Normal University, Shanghai 200241, China
P. Zhang: Technical Center for Multifunctional Magneto-Optical Spectroscopy (ECNU), Shanghai, China and Department of Electronic Engineering, East China Normal University, Shanghai 200241, China
L. P. Xu: Technical Center for Multifunctional Magneto-Optical Spectroscopy (ECNU), Shanghai, China and Department of Electronic Engineering, East China Normal University, Shanghai 200241, China
C. Chen: Jiangxi Key Laboratory of Advanced Ceramic Materials, Department of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333001, China
J. Z. Zhang: Technical Center for Multifunctional Magneto-Optical Spectroscopy (ECNU), Shanghai, China and Department of Electronic Engineering, East China Normal University, Shanghai 200241, China
Z. G. Hu: Technical Center for Multifunctional Magneto-Optical Spectroscopy (ECNU), Shanghai, China and Department of Electronic Engineering, East China Normal University, Shanghai 200241, China
H. S. Luo: R&D Center of Synthetic Crystals, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, China
J. H. Chu: Technical Center for Multifunctional Magneto-Optical Spectroscopy (ECNU), Shanghai, China and Department of Electronic Engineering, East China Normal University, Shanghai 200241, China

DOI: https://doi.org/10.1063/1.4966910
Journal volume & issue: Vol. 6, no. 10
pp. 105311 – 105311-8

Abstract

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Optical properties, electronic structures, and structural variations of x wt% cobalt (Co) doped Na0.5Bi0.5TiO3-6%BaTiO3 (x=0%, 0.5%, 0.8%) single crystals have been studied by temperature-dependent optical ellipsometry and Raman spectra from 250 to 650 K. Based on the temperature evolution of electronic transitions (Ecp1 and Ecp2) and the phonon modes involving Ti-O vibrations, two critical temperature points exhibit an increasing trend with Co dopants, which are related to structural variations for ferroelectric to anti-ferroelectric, and anti-ferroelectric to paraelectric transition, respectively. Additionally, distinguishing abnormal phonon behaviors can be observed from Raman spectra for the crystal of x=0.5% and 0.8%, which show reverse frequency shift of the modes involving Ti-O vibration. It can be ascribed to different relative concentration of Co2+ and Co3+ in the crystals, which has been confirmed by X-ray Photoelectron Spectroscopy data.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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