Dielectric and Ac Conductivity Studies of Mn-Doped Na1.86Li0.10K0.04Ti3O7 Ceramics
R. Singh and Shripal
Department of Physics, P.P.N. College, Kanpur-208001, India
Received: December 14, 2012; In final form: May 23, 2013
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Dielectric-spectroscopic and ac conductivity studies on 0.01 and 1.0 molar percentage manganese doped layered Na1.86Li0.10K0.04Ti3O7 ceramics have been reported. The dependence of loss tangent (tan δ) and relative permittivity (εr) on temperature in the range 350-775 K and on frequency in the range 10 kHz-1 MHz have been undertaken. The losses are the characteristics of dipole mechanism, electrical conduction and space charge polarization. The obtained conductivity plots between log(σacT) versus 1000/T have been divided into four regions namely region I, II, III, and IV. The mechanism of conduction in region I is acknowledged to electronic hopping conduction. The less frequency and more temperature dependent region II is ascribed as a mixed mechanism "associated interlayer ionic conduction, electron hopping, and alkali ion hopping conduction". The unassociated interlayer ionic conduction along with alkali ion hopping conduction mechanisms are contributing to the transport process in the mid temperature region III. The mechanism of conduction in the highest temperature region IV may be recognized as the modified interlayer ionic conduction. The conductivity versus frequency curves lead to conclude that the electronic hopping conduction diminishes with the rise of temperature.

DOI: 10.12693/APhysPolA.125.67
PACS numbers: 72.10.Bg, 72.20.Ee, 72.60.+g, 77.22.-d, 77.22.Gm, 77.22.Jp