Jump to main content
Jump to site search

Issue 5, 2017
Previous Article Next Article

Polaronic transport in iron phosphate glasses containing HfO2 and CeO2

Author affiliations

Abstract

The electrical and dielectric properties of three series of glasses, xHfO2–(40 − x)Fe2O3–60P2O5, 0 ≤ x ≤ 8 mol%, xCeO2–(40 − x)Fe2O3–60P2O5, 0 ≤ x ≤ 8 mol%, and xHfO2–(38 − x)Fe2O3–2B2O3–60P2O5 2 ≤ x ≤ 6 mol%, have been investigated by impedance spectroscopy over a wide frequency and temperature range. As expected, these glasses exhibit polaronic conductivity which strongly depends on the fraction of ferrous ions, Fe2+/Fetot. Following a detailed discussion on the DC conductivity, we use the MIGRATION concept to model their conductivity spectra. It is found that in each series of glasses, the shape of the conductivity isotherms remains the same indicating that the time-temperature superposition principle is satisfied and that the mechanism of conductivity is the same. Returning to a model-free scaling procedure, namely Summerfield scaling, it is found that while conductivity isotherms for each composition yield a master curve, we need to suitably shift individual master curves on the frequency axis to generate a super-master curve. We examine the dependence of the DC conductivity and the shift factors on the number density of charge carriers. Next, using the fact that the dielectric strength of relaxation for each isotherm is well-defined in these systems, we scale the conductivity isotherms using the Sidebottom scaling procedure. This procedure yields a super-master curve, implying that length scales for polaronic transport also change with composition. Further, using the scaling features of permittivity spectra, we extract in a straightforward way the characteristic spatial extent of localized hopping of polarons and find that it decreases with increasing number density of charge carriers. The magnitude of these values obtained from permittivity spectra lies in the same range as those for the polaron radius calculated using the equation proposed by Bogomolov and Mirilin.

Graphical abstract: Polaronic transport in iron phosphate glasses containing HfO2 and CeO2

Back to tab navigation

Publication details

The article was received on 16 Jun 2016, accepted on 09 Dec 2016 and first published on 09 Dec 2016


Article type: Paper
DOI: 10.1039/C6CP04226K
Phys. Chem. Chem. Phys., 2017,19, 3999-4009
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Polaronic transport in iron phosphate glasses containing HfO2 and CeO2

    A. Šantić, R. D. Banhatti, L. Pavić, H. Ertap, M. Yüksek, M. Karabulut and A. Moguš-Milanković, Phys. Chem. Chem. Phys., 2017, 19, 3999
    DOI: 10.1039/C6CP04226K

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements