Journal of Materials Research and Technology Journal of Materials Research and Technology
J Mater Res Technol 2017;6:7-12 DOI: 10.1016/j.jmrt.2016.03.002
Original Article
Electronic and ionic conductivity studies on microwave synthesized glasses containing transition metal ions
Basareddy Sujathaa, Ramarao Viswanathab, Hanumathappa Nagabushanac, Chinnappa Narayana Reddyd,,
a Department of Electronics & Communication, MSR Institute of Technology, Bangalore, India
b Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India
c Department of Physics, Tumkur University, Tumkur, India
d Department of Physics, Sree Siddaganga College of Arts, Science and Commerce, Tumkur University, Tumkur, India
Received 27 April 2015, Accepted 08 March 2016
Abstract

Glasses in the system xV2O5·20Li2O·(80x) [0.6B2O3:0.4ZnO] (where 10x50) have been prepared by a simple microwave method. Microwave synthesis of materials offers advantages of efficient transformation of energy throughout the volume in an effectively short time. Conductivity in these glasses was controlled by the concentration of transition metal ion (TMI). The dc conductivity follows Arrhenius law and the activation energies determined by regression analysis varies with the content of V2O5 in a non-linear passion. This non-linearity is due to different conduction mechanisms operating in the investigated glasses. Impedance and electron paramagnetic resonance (EPR) spectroscopic studies were performed to elucidate the nature of conduction mechanism. Cole–cole plots of the investigated glasses consist of (i) single semicircle with a low frequency spur, (ii) two depressed semicircles and (iii) single semicircle without spur, which suggests the operation of two conduction mechanisms. EPR spectra reveal the existence of electronic conduction between aliovalent vanadium sites. Further, in highly modified (10V2O5mol%) glasses Li+ ion migration dominates.

Keywords
Microwave synthesis, Semiconducting, Modulated DSC, Impedance, EPR study
J Mater Res Technol 2017;6:7-12 DOI: 10.1016/j.jmrt.2016.03.002