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The AC Conductivity of Liquid‐Phase‐Sintered Silicon Carbide
Author(s) -
Sauti Godfrey,
Can Antoinette,
McLachlan David S.,
Herrmann Mathias
Publication year - 2007
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.1551-2916.2007.01792.x
Subject(s) - grain boundary , materials science , silicon carbide , ceramic , conductivity , rietveld refinement , phase (matter) , dielectric , electrical resistivity and conductivity , immittance , analytical chemistry (journal) , grain size , condensed matter physics , composite material , mineralogy , microstructure , electronic engineering , chemistry , crystallography , optoelectronics , electrical engineering , organic chemistry , crystal structure , physics , chromatography , engineering
Analysis of the AC conductivity, complex dielectric constant, and the resulting immittance spectra of liquid‐phase‐sintered silicon carbide (SiC) ceramics showed that for this system, the dominant experimental observations are due to a multicomponent grain‐boundary phase and not due to SiC grains. This is confirmed by noting that the temperature dependence of the conductivity of the components, derived from the impedance spectra, is proportional to exp[−( T 0 / T ) 1/4 ] and not to exp[− C / T ]. The electrical properties of some of the grain boundaries are also found to be excitation voltage dependent. Combining the electrical results, which are also found to depend on the method of preparation and heat treatment, with a Rietveld analysis allows the composition of the grain boundaries of the models to be deduced.