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Dielectric Relaxations and Phase Transition in Laser Crystals Gd 2 SiO 5 and Yb ‐Doped Gd 2 SiO 5
Author(s) -
Liu Lina,
Wang Chunchang,
Zhang Deming,
Zhang Qinling,
Ning Kaijie,
Wang Jing,
Sun Xiaohong
Publication year - 2014
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.12807
Subject(s) - dielectric , materials science , atmospheric temperature range , doping , relaxation (psychology) , phase transition , analytical chemistry (journal) , transition temperature , temperature coefficient , condensed matter physics , chemistry , optoelectronics , physics , thermodynamics , social psychology , superconductivity , chromatography , composite material , psychology
The crystals Gd 2 SiO 5 and Yb ‐doped Gd 2 SiO 5 were grown by Czochralski method successfully. Dielectric properties of the two crystals were investigated in the temperature range from 100 to 1100 K and the frequency range from 20 Hz to 10 MHz. Our results revealed that these crystals show intrinsic dielectric behavior in the temperature below room temperature, whereas in above room temperature, a relaxor‐like dielectric anomaly and a metal–insulator transition were observed. It was found that the relaxor‐like anomaly contains two dielectric relaxations. Impedance analysis showed that the low‐ and high‐temperature relaxations are dipolar‐ and Maxwell–Wagner‐type relaxation, respectively. The transition was found to be strongly related to oxygen vacancies, which leads to positive temperature coefficient of resistance and an abnormal dielectric behavior contrary to the conventional thermally activated behavior at temperatures near the transition temperature.