Measurements of the lattice constant of ceria when doped with lanthana and praseodymia - The possibility of local defect ordering and the observation of extensive phase separation

K. M. Ryan, J. P. McGrath, R. A. Farrell, W. M. O'Neill, C. J. Barnes, M. A. Morris

Research output: Contribution to journalLetterpeer-review

Abstract

Conventionally, the addition of sesquioxide cation dopants to ceria has been thought of as a class of almost model systems. The most important defect mechanism involves simple anion vacancy charge compensation with those vacancy defects associating themselves with the trivalent cation and being distributed randomly through the lattice. However, this simple model has been significantly challenged in recent years and it seems possible that these associated defects might cluster in ordered arrangements. Whilst evidence has been provided by theoretical work, only limited experimental data are available. This letter reports the first observation of local ordering in these systems as observed by careful powder x-ray diffraction studies. In detail, it is shown that measurements of the lattice parameter do not vary monotonically with dopant concentration. It is also shown that far from being ideal systems with very high dopant solubilities and true solid-state solutions, these systems have complex solubility.

Original languageEnglish
Pages (from-to)L49-L58
JournalJournal of Physics Condensed Matter
Volume15
Issue number2
DOIs
Publication statusPublished - 22 Jan 2003
Externally publishedYes

Fingerprint

Dive into the research topics of 'Measurements of the lattice constant of ceria when doped with lanthana and praseodymia - The possibility of local defect ordering and the observation of extensive phase separation'. Together they form a unique fingerprint.

Cite this