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The polycrystalline samples of complex tungsten bronze (TB) Na2Pb2R2W2Ti4V4O30 (R=Dy, Pr) compounds were prepared by solid-state reaction technique. Room- temperature preliminary structural studies confirm the formation of the compounds in the orthorhombic crystal system. Detailed studies of electrical properties of the materials using complex impedance spectroscopy technique exhibit that the impedance and related parameters are strongly dependent upon temperature and microstructure (bulk, grain boundary, etc). An observation of negative temperature coefficient of resistance (NTCR) suggests the materials have semiconducting properties. The variation of AC conductivity with temperature shows a typical Arrhenius behavior of the materials. Both the samples obey Jonscher’s universal power law. The existence of hopping mechanism in the electrical transport processes in the system with non-exponential type of conductivity relaxation is confirmed by electrical modulus analysis.


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Electrical properties of Na2Pb2R2W2Ti4V4O30 (R = Dy, Pr) ceramics

Show Author's information Piyush R. DAS*( )B. N. PARIDAR. PADHEER. N. P. CHOUDHARY
Department of Physics, Institute of Technical Education & Research, Siksha ‘O’ Anusandahan University, Khandagiri, Bhubaneswar 751030, Odisha, India

Abstract

The polycrystalline samples of complex tungsten bronze (TB) Na2Pb2R2W2Ti4V4O30 (R=Dy, Pr) compounds were prepared by solid-state reaction technique. Room- temperature preliminary structural studies confirm the formation of the compounds in the orthorhombic crystal system. Detailed studies of electrical properties of the materials using complex impedance spectroscopy technique exhibit that the impedance and related parameters are strongly dependent upon temperature and microstructure (bulk, grain boundary, etc). An observation of negative temperature coefficient of resistance (NTCR) suggests the materials have semiconducting properties. The variation of AC conductivity with temperature shows a typical Arrhenius behavior of the materials. Both the samples obey Jonscher’s universal power law. The existence of hopping mechanism in the electrical transport processes in the system with non-exponential type of conductivity relaxation is confirmed by electrical modulus analysis.

Keywords: microstructure, electrical properties, ferroelectricity, ceramics, impedance spectroscopy

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Publication history

Received: 11 January 2013
Revised: 06 February 2013
Accepted: 16 February 2013
Published: 04 June 2013
Issue date: June 2013

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© The author(s) 2013

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Open Access: This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

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