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Nanocrystalline Nd2–yGdyZr2O7 pyrochlore: Facile synthesis and electrical characterization

Published online by Cambridge University Press:  31 January 2011

Balaji P. Mandal ,
Atanu Dutta ,
S.K. Deshpande ,
R.N. Basu  and
Avesh K. Tyagi
Balaji P. Mandal
Affiliation:
Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
Atanu Dutta
Affiliation:
Central Glass and Ceramic Research Institute, CSIR, Kolkata 700032, India
S.K. Deshpande
Affiliation:
UGC-DAE Consortium for Scientific Research, Bhabha Atomic Research Centre, Mumbai 400085, India
R.N. Basu
Affiliation:
Central Glass and Ceramic Research Institute, CSIR, Kolkata 700032, India
Avesh K. Tyagi*
Affiliation:
Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
*
a) Address all correspondence to this author. e-mail: aktyagi@barc.gov.in
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Abstract

Three solid solutions of pyrochlores in the series Nd2-yearsGdyZr2O7 (y = 0.8, 1.0, 1.2) were synthesized by the gel combustion method using citric acid as fuel. This results in a soft agglomerate powder as verified by dynamic light scattering. The single-phase nature of the products has been confirmed by x-ray diffraction. The increase in full width at half-maxima in the Raman spectra with an increase in Gd3+ content indicates that disorder increases with Gd3+ content. The morphology and particle size of the products were investigated by transmission electron microscopy. Scanning electron microscopy study reveals that the sintered pellets have a density higher than 92% of theoretical densities. The total ionic conductivity measurements in the temperature range 375–800 °C show that with the increase of disorder (Gd3+ content) in the system the activation energy of conduction increases from 0.98 to 1.06 eV and the preexponential factor, which is proportional to the number of mobile species, also follow the same trend of increase. The total conductivity measured in reducing atmosphere shows no change in electrical conductivity, which verifies a negligible contribution of electronic contribution in this system.

Keywords

Ionic conductorNanostructureX-ray diffraction (XRD)
Type
Articles
Information
Journal of Materials Research , Volume 24 , Issue 9 , September 2009 , pp. 2855 - 2862
Copyright
Copyright © Materials Research Society 2009

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