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Dielectric and electric relaxations induced by the complex defect clusters in (Yb+Nb) co‐doped rutile TiO 2 ceramics
Author(s) -
Zhao Xiaogang,
Liu Peng
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14861
Subject(s) - polaron , materials science , dielectric , condensed matter physics , doping , rutile , permittivity , conductivity , electrical resistivity and conductivity , microstructure , ceramic , analytical chemistry (journal) , mineralogy , electron , chemistry , physics , metallurgy , optoelectronics , chromatography , organic chemistry , quantum mechanics
The effect of the Yb+Nb substitution for Ti on the microstructure, crystal structures, and dielectric properties of (Yb 1/2 Nb 1/2 ) x Ti 1− x O 2 (0.01≤ x ≤0.1) ceramics is investigated in this study. The results reveal that the solid solubility limit of the (Yb 1/2 Nb 1/2 ) x Ti 1− x O 2 ceramics is x =0.07, and the average grain sizes considerably decrease from 12 μm to 6 μm with x increasing from 0.01 to 0.1. Three types of dielectric relaxations are observed at temperature ranges of 10‐30 K, 80‐180 K, and 260‐300 K, caused by the electron‐pinned defect dipoles, polaron hopping, and interfacial polarizations, respectively. The conduction mechanism changes from nearest‐neighbor‐hopping to polaron hopping mechanism, which is confirmed by ac conductivity measurements. The present work indentifies the correlation between the colossal permittivity and polaron hopping process in the titled compound.