Open AccessImpedance spectroscopy studies on lead free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 ceramics
Author(s) -
Ahcène Chaouchi,
Sadia Kennour
Publication year - 2012
Publication title -
processing and application of ceramics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.326
H-Index - 15
eISSN - 2406-1034
pISSN - 1820-6131
DOI - 10.2298/pac1204201c
Subject(s) - nyquist plot , materials science , grain boundary , dielectric spectroscopy , ceramic , analytical chemistry (journal) , crystallite , dielectric , atmospheric temperature range , temperature coefficient , activation energy , relaxation (psychology) , condensed matter physics , thermal conduction , electrical resistivity and conductivity , electrical impedance , thermodynamics , composite material , microstructure , chemistry , optoelectronics , electrical engineering , metallurgy , electrode , psychology , social psychology , physics , organic chemistry , chromatography , electrochemistry , engineering
The AC complex impedance spectroscopy technique has been used to obtain the electrical parameters of polycrystalline sample of (Ba0.85Ca0.15) (Ti0.9Zr0.1)O3 in a wide frequency range at different temperatures. This sample was prepared by a high temperature solid-state reaction technique and single phase formation was confirmed by X-ray diffraction technique. This study was carried out by the means of simultaneous analysis of impedance, modulus, and electrical conductivity. The Cole-Cole (Nyquist) plots suggest that the grains and grain boundaries are responsible in the conduction mechanism of the material at high temperature. The Cole- Cole (Nyquist) plot studies revealed the presence of grain and grain boundary effect at 485 ?C. On the other hand, it showed only the presence of grain boundary component of the resistivity at 535 ?C. Complex impedance analysis indicated the presence of non-Debye type dielectric relaxation. The bulk resistance of the material decreases with rise in temperature similar to a semiconductor, and the Cole-Cole (Nyquist) plot showed the negative temperature coefficient of resistance (NTCR) character of (Ba0.85Ca0.15 )(Ti0.9Zr0.1 )O3. The value of activation energy is found to be 0.7433 eV, which suggests that the conduction may be the result of defect and charge carriers present in the materials.