Premium
Dielectric Loss Spectrum of Ceramic MgTiO 3 Investigated by AC Impedance and Microwave Resonator Measurements
Author(s) -
Kuang Xiaojun,
Jing Xiping,
Tang Zongxi
Publication year - 2006
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/j.1551-2916.2005.00669.x
Subject(s) - dielectric loss , materials science , dielectric , microwave , dielectric spectroscopy , atmospheric temperature range , ceramic , arrhenius equation , chemistry , optoelectronics , composite material , activation energy , physics , thermodynamics , organic chemistry , electrode , quantum mechanics , electrochemistry
MgTiO 3 ceramic was selected as a model material of the microwave dielectric ceramics for the investigation of the dielectric loss spectrum. Conductivity spectra in the low‐frequency range 1–10 6 Hz at elevated temperatures and the dielectric loss spectrum in the microwave range 6–14 GHz at room temperature were characterized by AC impedance spectroscopy and the microwave resonator method, respectively. The experimental data were analyzed by using Jonscher's universal power law, the Arrhenius equation as well as the classic dispersion theory. Consequently, a dielectric loss spectrum (tg δ∼ f plot) at room temperature in a wide frequency range was obtained. Based on the loss spectrum, the dielectric loss can be classified into three mechanisms in MgTiO 3 ceramic (each dominates the loss in different frequency ranges): DC conductance (in DC field), AC conductance (<10 7 Hz), and anharmonicity of lattice vibration (in GHz range). The influence of defects on the microwave dielectric loss possibly is because of atom defects via damage of the perfection of lattice and modification of the anharmonic force in lattice, while the electronic defects trapped on the atomic defects affect the DC and AC losses.