Influence of Oxygen Vacancies on the Impedance Spectrum of Al2O3-Na0.5K0.5NbO3 Composites

Martin A, Webber KG, Kakimoto KC (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Crystals MDPI

Book Volume: 13

Journal Issue: 3

DOI: 10.3390/cryst13030463

Abstract

Composites based on ferroelectric Na0.5K0.5NbO3 (NKN) and paraelectric Al2O3 were observed using impedance spectroscopy at different temperatures. This allowed for the evaluation of the conduction processes of the bulk and grain boundary, revealing the occurrence of interdiffusion and changes in the conductive properties. The effective conductivity decreased with the increase in Al2O3, which is due to the highly resistive nature of Al2O3. Interestingly, the activation energy for the bulk response increased from 0.87 +/- 0.06 eV to approximately 1.12 +/- 0.03 eV, and the activation energy of the grain boundary decreased from 1.26 +/- 0.09 eV to 0.99 +/- 0.09 eV. These observations of the activation energy revealed the interdiffusion of Al3+ ions, leading to the formation of oxygen vacancies in close vicinity to the grain boundary. As a result, the conduction path for charge carriers shifted to take place predominantly along the grain boundary.

Authors with CRIS profile

Kyle Grant Webber Professur für Werkstoffwissenschaften (Funktionskeramik)

Additional Organisation(s)

Graduiertenkolleg 2495/2 Energiekonvertierungssysteme: von Materialien zu Bauteilen (Energy Conversion Systems: From Materials to Devices)

Involved external institutions

Nagoya Institute of Technology / 名古屋工業大学 Nagoya Kōgyō Daigaku JP Japan (JP)

How to cite

APA:

Martin, A., Webber, K.G., & Kakimoto, K.-C. (2023). Influence of Oxygen Vacancies on the Impedance Spectrum of Al2O3-Na0.5K0.5NbO3 Composites. Crystals, 13(3). https://doi.org/10.3390/cryst13030463

MLA:

Martin, Alexander, Kyle Grant Webber, and Keni-Chi Kakimoto. "Influence of Oxygen Vacancies on the Impedance Spectrum of Al2O3-Na0.5K0.5NbO3 Composites." Crystals 13.3 (2023).

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