Structural and dynamic properties of oxygen vacancies in perovskite oxides--analysis of defect chemistry by modern multi-frequency and pulsed EPR techniques.
Summary of "Structural and dynamic properties of oxygen vacancies in perovskite oxides--analysis of defect chemistry by modern multi-frequency and pulsed EPR techniques."
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', ) such that valency altered acceptor states or defect complexes are formed. Additionally, the trapping of charge carriers at the intrinsic 'reduced' B-site ions, and , can be observed by means of EPR spectroscopy.
Affiliation
Institut für Physikalische Chemie I, Universität Freiburg, Albertstr. 21, D-79104 Freiburg, Germany. ruediger.eichel@physchem.uni-freiburg.de
Journal Details
This article was published in the following journal.
Name: Physical chemistry chemical physics : PCCP
ISSN: 1463-9084
Pages: 368-84
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21082136
- DOI: http://dx.doi.org/10.1039/b918782k
Medical and Biotech [MESH] Definitions
Oxides
Binary compounds of oxygen containing the anion O(2-). The anion combines with metals to form alkaline oxides and non-metals to form acidic oxides.
Cyclic N-oxides
Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.
Biological Oxygen Demand Analysis
Testing for the amount of biodegradable organic material in a water sample by measuring the quantity of oxygen consumed by biodegradation of those materials over a specific time period.
Heterocyclic Oxides
Oxides of a ring compound having atoms other than carbon in its ring.
Sulfur Oxides
Inorganic oxides of sulfur.
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