Yang, F., Li, L., Wu, P. et al. (3 more authors) (2018) Use of the time constant related parameter fmax to calculate the activation energy of bulk conduction in ferroelectrics. Journal of Materials Chemistry C, 6 (34). pp. 9258-9268. ISSN 2050-7526
Abstract
The activation energy associated with bulk electrical conduction in functional materials is an important quantity which is often determined by impedance spectroscopy using an Arrhenius-type equation. This is achieved by linear fitting of bulk conductivity obtained from complex (Z*) impedance plots versus T-1 which gives an activation energy Ea(σ) or by linear fitting of the characteristic frequency fmax obtained from the large Debye peak in M’’-logf spectroscopic plots against T-1 which gives an activation energy Ea(fmax). We report an analysis of Ea(σ) and Ea(fmax) values for some typical non-ferroelectric and ferroelectric materials and employ numerical simulations to investigate combinations of different conductivity-temperature and permittivity-temperature profiles on the logfmax – T-1 relationship and Ea(fmax). Results show the logfmax – T-1 relationship and Ea(fmax) are strongly dependent on the permittivity-temperature profile and the temperature range measured relative to Tm (temperature of the permittivity maximum). Ferroelectric materials with a sharp permittivity peak can result in non-linear logfmax – T-1 plots in the vicinity of Tm. In cases where data are obtained either well above or below Tm, linear logfmax – T-1 plots can be obtained but overestimate or underestimate the activation energy for conduction, respectively. It is therefore not recommended to use Ea(fmax) to obtain the activation energy for bulk conduction in ferroelectric materials, instead Ea(σ) should be used.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 Royal Society of Chemistry. This is an author produced version of a paper subsequently published in Journal of Materials Chemistry C. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 14 Aug 2018 10:05 |
Last Modified: | 26 Aug 2020 07:45 |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Refereed: | Yes |
Identification Number: | 10.1039/C8TC03011A |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:134547 |