Record Details

Impedance and Electric Modulus Spectroscopy of Polycrystalline La0.5Sr0.5Bi0.2Co0.4Fe0.4O3– Cathode Ceramic for Intermediate Temperature SOFCs

NOPR - NISCAIR Online Periodicals Repository

View Archive Info
 
 
Field Value
 
Title Impedance and Electric Modulus Spectroscopy of Polycrystalline La0.5Sr0.5Bi0.2Co0.4Fe0.4O3– Cathode Ceramic for Intermediate Temperature SOFCs
 
Creator Singh, Sunder
Kumar, Manindra
Kumar, Anil
Saini, Deepash Shekhar
 
Subject Cathode materials
Grain boundary
Porous
Impedance
Electric modulus
Jonscher’s double power law
 
Description 549-558
In the present research work, La0.5Sr0.5Bi0.2Co0.4Fe0.4O3– cathode ceramic powder is synthesized through cost-effective
flash pyrolysis process and followed by conventional sintering for IT-SOFCs. The Rietveld refinement program is used to
determine the crystal structure, unit cell parameters and bond length. The XRD result indicates existence of a pure single
phase of rhombohedral structure with R3􀴤
C space group symmetry detected from the sample sintered at 700 ℃. FESEM
micrographs of fracture surface of sample sintered at 700 ℃ showed a high porosity and nano grain sizes (50-100 nm).
Combined impedance and electric modulus spectroscopic are used to investigate the relaxation phenomena in
La0.5Sr0.5Bi0.2Co0.4Fe0.4O3– ceramic over a broad range of temperature and frequency. A single relaxation peak is observed
in the imaginary part of impedance and electric modulus spectra, which could be due to the contribution of grain boundary
of La0.5Sr0.5Bi0.2Co0.4Fe0.4O3– ceramic. The imaginary part of modulus (𝑀") spectra is studied with help of non-exponential
decay function or Kohlrausch–Williams–Watts (KWW) parameter (β). In the combined plot of the imaginary part of
impedance (𝑍") and electric modulus (𝑀") spectra at 210 ℃, only a single peak of 𝑍"and 𝑀" is observed at the same
frequency which specifies that the conduction process is a long-range motion of the charge carriers. The frequencydependent
conductivity is followed by the Jonscher’s double power law in the temperature range 30-210 ℃.
 
Date 2021-08-23T11:36:35Z
2021-08-23T11:36:35Z
2021-08
 
Type Article
 
Identifier 0975-0959 (Online); 0301-1208 (Print)
http://nopr.niscair.res.in/handle/123456789/57939
 
Language en
 
Publisher NIScPR-CSIR, India
 
Source IJPAP Vol.59(08) [August 2021]