The effect of dysprosium and strontium on the total ionic conductivity of ceria in the system Ce1-xDyx-ySryO2-δ was studied. In this system, few compositions were prepared with x=0.15, y=0.015, 0.03 and 0.045 by modi...The effect of dysprosium and strontium on the total ionic conductivity of ceria in the system Ce1-xDyx-ySryO2-δ was studied. In this system, few compositions were prepared with x=0.15, y=0.015, 0.03 and 0.045 by modified sol-gel process using maltose and pectin as organic precursors. Rietveld refinement of XRD patterns confirms the cubic structure with space group Fm3m . SEM images show relatively uniform grains with clean and distinct grain boundaries. Four probe AC impedance measurements were carried out to evaluate the total ionic conductivity in the temperature range of 150-500 ℃ and frequency range of 40 Hz-1 MHz. The composition Ce0.85Dy0.12Sr0.03O2-δshows higher electrical conductivity than single-doped ceria samples.展开更多
In this communication,the electrical conductivities and thermal expansion studies of microwave sintered co-doped ceria Ce_(0.8)Y_(0.2-x)Dy_(x)O_(2-δ)(x=0,0.05,0.10,0.15 and 0.20) solid electrolyte materials for inter...In this communication,the electrical conductivities and thermal expansion studies of microwave sintered co-doped ceria Ce_(0.8)Y_(0.2-x)Dy_(x)O_(2-δ)(x=0,0.05,0.10,0.15 and 0.20) solid electrolyte materials for intermediate temperature solid oxide fuel cells(IT-SOFCs)synthesized by sol-gel auto-combustion method were discussed.Microwave sintering at 1300℃ for 30 min was used for making dense powder compacts.The relative densities of all the samples are noticed above 95%.Raman spectrum was characterized by the presence of a very strong band near 460 cm^(-1),which along with X-ray diffraction(XRD) analysis ascertain the sample formation with a single-phase cubic fluorite structure.The lattice parameter values were calculated from XRD patterns.SEM images show nearly uniform grains with distinct grain boundaries.The thermal expansion coefficients(TECs) are found to vary linearly with temperature and were measured in the range from 14.15 to 13.20×10^(-6)℃^(-1).The investigation on total ionic conductivity(TIC) was executed with variation in dopant concentration and relative oxygen vacancies.The impedance analysis reveals that the sample Ce_(0.80)Y_(0.10)Dy_(0.10)O_(2-δ) displays the highest TIC,i.e.,7.5×10^(-3) S·cm^(-1) at 500℃ and minimum activation energy 0.90 eV compared to others.With the highest TIC and minimum activation energy,the Ce_(0.80)Y_(0.10)Dy_(0.10)O_(2-δ)might be the possible material as the solid electrolyte in intermediate temperature SOFCs.展开更多
基金the UGC for providing financial assistance under DSKPDF, BSR project No. F.4-2/2006(BSR)/13-389/2010 (BSR)
文摘The effect of dysprosium and strontium on the total ionic conductivity of ceria in the system Ce1-xDyx-ySryO2-δ was studied. In this system, few compositions were prepared with x=0.15, y=0.015, 0.03 and 0.045 by modified sol-gel process using maltose and pectin as organic precursors. Rietveld refinement of XRD patterns confirms the cubic structure with space group Fm3m . SEM images show relatively uniform grains with clean and distinct grain boundaries. Four probe AC impedance measurements were carried out to evaluate the total ionic conductivity in the temperature range of 150-500 ℃ and frequency range of 40 Hz-1 MHz. The composition Ce0.85Dy0.12Sr0.03O2-δshows higher electrical conductivity than single-doped ceria samples.
基金financially supported by the University Grants Commission,New Delhi,India,under the scheme of Faculty Development Program (No.Lr.APKA028/001/XIIPLAN)。
文摘In this communication,the electrical conductivities and thermal expansion studies of microwave sintered co-doped ceria Ce_(0.8)Y_(0.2-x)Dy_(x)O_(2-δ)(x=0,0.05,0.10,0.15 and 0.20) solid electrolyte materials for intermediate temperature solid oxide fuel cells(IT-SOFCs)synthesized by sol-gel auto-combustion method were discussed.Microwave sintering at 1300℃ for 30 min was used for making dense powder compacts.The relative densities of all the samples are noticed above 95%.Raman spectrum was characterized by the presence of a very strong band near 460 cm^(-1),which along with X-ray diffraction(XRD) analysis ascertain the sample formation with a single-phase cubic fluorite structure.The lattice parameter values were calculated from XRD patterns.SEM images show nearly uniform grains with distinct grain boundaries.The thermal expansion coefficients(TECs) are found to vary linearly with temperature and were measured in the range from 14.15 to 13.20×10^(-6)℃^(-1).The investigation on total ionic conductivity(TIC) was executed with variation in dopant concentration and relative oxygen vacancies.The impedance analysis reveals that the sample Ce_(0.80)Y_(0.10)Dy_(0.10)O_(2-δ) displays the highest TIC,i.e.,7.5×10^(-3) S·cm^(-1) at 500℃ and minimum activation energy 0.90 eV compared to others.With the highest TIC and minimum activation energy,the Ce_(0.80)Y_(0.10)Dy_(0.10)O_(2-δ)might be the possible material as the solid electrolyte in intermediate temperature SOFCs.
