The composite solid electrolytes, NaNO3 dispersed with Al2O3, CeO2, ZrO2 and SiO2 have been prepared by melt quenching method and investigated through XRD, DSC and electrical conductivity techniques. Typical increase in conductivity is about two orders of magnitude for 10 mol% of Al2O3 at 200 °C. The electronic transference number evaluated through dc polarization method was found out to be 1 × 10-2 at 200 °C. The dependence of conductivity on concentration of dispersoids and particle size is in accordance with the space charge theory of conduction. The enhanced conductivity of NaNO3 homogenously doped by Ca(NO3)2 was further enhanced by heterogeneous doping of Al2O3. By the contribution of these doping processes, the conductivity is enhanced by three orders of magnitude at 200 °C. The experimental and theoretically calculated values of conductivity using Maier's space charge layer model are in reasonable agreement. © 2003 Elsevier Science Ltd. All rights reserved.

P. S. Anantha

Krishnaswamy Hariharan

Differential scanning calorimetry

Doping (additives)

electric conductivity

ELECTRIC SPACE CHARGE

Inclusions

Interfaces (materials)

Ionic conduction

Quenching

Solid electrolytes

Transport properties

X ray diffraction analysis

DISPERSED OXIDE INCLUSIONS

Sodium compounds

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Enhanced ionic conduction in NaNO3 by dispersed oxide inclusions

Journal of Physics and Chemistry of Solids

This review article presents a brief overview of synthesis and application aspects of fast fluoride ion conducting materials in the field of Solid State Ionics. Possible synthesis methodologies known in the literature for the preparation of various fluoride materials have been outlined. Further, their transport characteristics with respect to their crystal structure have been discussed. Various approaches influencing their ionic conductivity value in the light of synthesis methodology, composition, dopant concentration, crystallite size, microstructure etc. have been reviewed. At the end, possible technological applications of fast fluoride ion conducting materials in different solid state ionic devices have been presented. © 2013 Elsevier B.V.

Solid State Ionics

Fast fluoride ion conducting materials in solid state ionics: An overview

The composite solid electrolytes, NaSn2F5, dispersed with submicron size Al2O3 fillers of various concentrations and particle sizes have been synthesized through mechanochemical milling technique. X-ray diffraction and microstructure results indicate the biphasic nature of the composite materials. The transport properties of the present composite materials have been investigated by means of impedance spectroscopy, and the results show that the improvement in conductivity increases with decrease in the particle size of the filler. An enhancement in conductivity of two orders in magnitude is obtained for NaSn2F5 with Al2O3 dopant concentration of 10 mol%. The activation energy responsible for conductivity relaxation, calculated from the modulus spectra, is found to be almost the same as the value obtained from temperature variation of dc conductivity. The scaling result of the imaginary part of the modulus shows the temperature-independent relaxation behavior. © 2012 Springer-Verlag.

Ionics

Influence of dispersed alumina particles on the transport characteristics of mechanochemically synthesized NaSn2F5

Solid polymer electrolyte thin films based on poly(ethylene oxide) (PEO) complexed with NaNO3 salt with compositions between 2 and 10 ether oxygens per sodium have been prepared using the solution cast method as a possible sodium ion-conducting polymer electrolyte system. The complexation of the films has been investigated through X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) measurements. Electrical properties have been measured as a function of composition and temperature using complex impedance spectroscopy. The maximum ionic conductivity has been found to be ∼3.5×10-6 S/cm at room temperature for the composition O/Na=3:l. The transference numbers of different mobile species have been determined by means of DC polarization and combined AC/DC techniques. The complex impedance data have been analysed in conductivity and permittivity formalisms to cast light on possible ion transport mechanisms. The peaks found in the electric modulus plot have been characterized in terms of the stretched exponential parameter. © 2004 Elsevier B.V. All rights reserved.

Physical and ionic transport studies on poly(ethylene oxide)-NaNO 3 polymer electrolyte system

The electrical conductivity of NaNO3-xAl2O 3 composites has been studied over the wide range of temperature and frequency by means of impedance spectroscopy. The real part of the frequency dependent conductivity exhibits a simple power law feature and the dimensionless frequency exponent n has been determined. The conductivity spectra show scaling behaviour when the conductivity spectra are scaled by σdcT, where T is temperature in Kelvin. The real part of dielectric permittivity shows saturation at higher frequencies and a strong dispersion at lower frequencies. The imaginary part of permittivity varies inversely with frequency, due to the presence of dc conductivity. The frequency dependent plots of M″ and Z″ show that the conductivity relaxation is non-Debye in nature. The Kohlrausch-Williams-Watts stretched exponential function was used to describe the modulus spectra and the stretching exponent β is found to be temperature independent. The conductivity relaxation time has been estimated from the modulus spectra. The activation energy responsible for relaxation has been evaluated and it was found to be almost same as that of dc conductivity. © 2005 Elsevier B.V. All rights reserved.

Materials Science and Engineering B: Solid-State Materials for Advanced Technology

Ac conductivity analysis and dielectric relaxation behaviour of NaNO 3-Al2O3 composites

Who Was Who

Ramachandra Rao, Dewan Bahadur Sir M., (21 Sept. 1868–16 May 1936), President, The Madras Cooperative Central Land Mortgage Bank, Madras, India; Director, Reserve Bank of India

Defect and Diffusion Forum

Composite Solid Electrolytes

A mesoscopic heterostructure as the origin of the extreme ionic conductivity in AgI:Al2O3

Progress in Solid State Chemistry

Ionic conduction in space charge regions

Journal of The Electrochemical Society

Enhancement of the Fluoride Vacancy Conduction in PbF[sub 2]: SiO[sub 2] and PbF[sub 2]: Al[sub 2]O[sub 3] Composites

Journal	Journal of Physics and Chemistry of Solids
ISSN	00223697
Open Access	No