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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effects of sintering process on the structural, dielectric, and optical absorption properties of KNbO3-based ceramics

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Author(s):
Gennari, Ronaldo C. [1] ; Lang, Rossano [1] ; Eiras, Jose A. [2] ; Lente, Manuel H. [1]
Total Authors: 4
Affiliation:
[1] Univ Fed Sao Paulo, Inst Ciencia & Tecnol, Sao Jose Dos Campos - Brazil
[2] Univ Fed Sao Carlos, Dept Fis, Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Journal of the American Ceramic Society; v. 102, n. 7, p. 3923-3931, JUL 2019.
Web of Science Citations: 1
Abstract

The influence of the sintering temperature and the dwell time on the structural, optical, and dielectric properties of {[}KNbO3](0.8){[}Ba(Ni0.5Nb0.5)O3-](0.2) ceramics (KBNNO) was systematically investigated. X-ray diffraction measurements of the ceramic bodies sintered at different temperatures indicated that all samples presented a cubic-like structure. However, the results remarkably revealed that both the sintering temperature and the dwell time are crucial factors that must be taken into account for tuning the optical response of the KBNNO ceramics. It was concluded that fine distortions in the (Nb,Ni)O-6 octahedral site, induced by sintering temperature and dwell time, promoted subtle changes in the local crystal field and, consequently, in the optical properties of the KBNNO. The mechanisms responsible for the observed spectral features of KBNNO were discussed by considering absorbance spectra of NiNb2O6 ceramics and allowed ligand-field transitions. The comparison between both optical spectra revealed a notable similarity between them. Since the octahedral site in KBNNO is equivalent to the nickel columbite structure, it was inferred that the spectral behavior is mainly driven by the same two contributions: one major associated to a distorted octahedral configuration and one minor related to spin-orbit coupling effects. In accordance with X-ray diffraction data, the temperature dependence of the dielectric properties corroborated that the KBNNO present a cubic-like phase in the whole temperature range investigated. (AU)

FAPESP's process: 17/13769-1 - Multiferroic and ferroelectric materials for energy converters: synthesis, properties, phenomenology and applications
Grantee:José Antonio Eiras
Support Opportunities: Research Projects - Thematic Grants