| EPSRC Reference: |
GR/S75833/01 |
| Title: |
New microwave dielectric oxides designed by vacancy ordering in hexagonal perovskites |
| Principal Investigator: |
Rosseinsky, Professor M |
| Other Investigators: |
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| Project Partners: |
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| Department: |
Chemistry |
| Organisation: |
University of Liverpool |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
10 August 2004 |
Ends: |
30 September 2004 |
Value (£): |
203,755
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| EPSRC Research Topic Classifications: |
| Materials Characterisation |
Materials Processing |
| Materials Synthesis & Growth |
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Summary on Grant Application Form |
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Cation ordering on the octahedral site of cubic perovskites is a well-exploited route to microwave dielectric oxide materials with high 0 (low loss) and near zero temperature coefficient of the resonant frequency (tf). We have recently discovered a series of phases in which vacancies on the octahedral sites enforce the insertion of hexagonal motifs into the cubic A03 sequence of the perovskite, and the vacancies are further ordered within the hexagonal region of the structure by the presence of d10 Zn2+ cations. This strongly suggests that the structures and dielectric figures of merit can be tuned by control of the density and detailed chemical nature of these hexagonal regions of the structure. We propose a systematic programme to investigate this structure-property-composition relation. The project couples synthesis of designed structures with dielectric property measurements and in-situ measurements of ceramic processing. The driving force for site-ordering imposed by the vacancies gives the opportunity to prepare cation - and site-ordered niobate phases that are hard to access in systems with fully occupied octahedral sites.
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.liv.ac.uk |