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Structural and dynamic properties of oxygen vacancies in perovskite oxides—analysis of defect chemistry by modern multi-frequency and pulsed EPR techniques

Eichel, Rüdiger-A. (2011):
Structural and dynamic properties of oxygen vacancies in perovskite oxides—analysis of defect chemistry by modern multi-frequency and pulsed EPR techniques.
In: Physical Chemistry Chemical Physics, pp. 368-384, 13, (2), ISSN 1463-9076, [Online-Edition: http://dx.doi.org/10.1039/b918782k],
[Article]

Abstract

Multi-frequency and pulsed electron paramagnetic resonance (EPR) provides a sensitive spectroscopic tool to elucidate the defect structure of transition-metal doped perovskite oxides, as well as to monitor dynamic processes of oxygen vacancies in these materials. In this regard, high-frequency EPR spectrometers and pulsed EPR techniques such as the hyperfine sublevel correlation experiment (HYSCORE) may now routinely be used for dedicated investigations, providing considerably more insight than the application of standard continuous-wave EPR. Recent results include the formation of defect complexes between acceptor-type transition-metal centers with either one or two oxygen vacancies for the reason of charge compensation. Furthermore, such defect complexes follow the domain switching upon poling ferroelectric compounds with correspondingly high electric fields. On the other hand, multi-valent manganese functional centers provide trapping centers for electronic and ionic charge carriers (e′, V0°°) such that valency altered Mn'n acceptor states or (Mn''n-V0°°) defect complexes are formed. Additionally, the trapping of charge carriers at the intrinsic ‘reduced’ B-site ions, Ti'n and (Ti'n-V0°°), can be observed by means of EPR spectroscopy.

Item Type: Article
Erschienen: 2011
Creators: Eichel, Rüdiger-A.
Title: Structural and dynamic properties of oxygen vacancies in perovskite oxides—analysis of defect chemistry by modern multi-frequency and pulsed EPR techniques
Language: English
Abstract:

Multi-frequency and pulsed electron paramagnetic resonance (EPR) provides a sensitive spectroscopic tool to elucidate the defect structure of transition-metal doped perovskite oxides, as well as to monitor dynamic processes of oxygen vacancies in these materials. In this regard, high-frequency EPR spectrometers and pulsed EPR techniques such as the hyperfine sublevel correlation experiment (HYSCORE) may now routinely be used for dedicated investigations, providing considerably more insight than the application of standard continuous-wave EPR. Recent results include the formation of defect complexes between acceptor-type transition-metal centers with either one or two oxygen vacancies for the reason of charge compensation. Furthermore, such defect complexes follow the domain switching upon poling ferroelectric compounds with correspondingly high electric fields. On the other hand, multi-valent manganese functional centers provide trapping centers for electronic and ionic charge carriers (e′, V0°°) such that valency altered Mn'n acceptor states or (Mn''n-V0°°) defect complexes are formed. Additionally, the trapping of charge carriers at the intrinsic ‘reduced’ B-site ions, Ti'n and (Ti'n-V0°°), can be observed by means of EPR spectroscopy.

Journal or Publication Title: Physical Chemistry Chemical Physics
Volume: 13
Number: 2
Divisions: DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > B - Characterisation > Subproject B1: EPR-Investigations of defects in ferroelectric ceramic material
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > B - Characterisation
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue
Zentrale Einrichtungen
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres
DFG-Collaborative Research Centres (incl. Transregio)
Date Deposited: 08 Aug 2011 09:07
Official URL: http://dx.doi.org/10.1039/b918782k
Additional Information:

SFB 595 B1

Identification Number: doi:10.1039/b918782k
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