| EPSRC Reference: |
EP/D506360/1 |
| Title: |
Ultrafast Dynamics in Magnetic Oxides |
| Principal Investigator: |
Thompson, Professor SM |
| Other Investigators: |
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| Department: |
Physics |
| Organisation: |
University of York |
| Scheme: |
Overseas Travel Grants Pre-FEC |
| Starts: |
06 June 2005 |
Ends: |
05 March 2006 |
Value (£): |
2,136
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| EPSRC Research Topic Classifications: |
| Materials Characterisation |
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Summary on Grant Application Form |
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Complex magnetic oxides exhibit a wide variety of magnetic and transport properties. Small changes in composition, structure, temperature or magnetic field can switch their electrical behaviour from insulating to metallic and their magnetic behaviour from antiferromagnetic to ferromagnetic. Recent interest has been fuelled by the observation of colossal magnetoresistance and the potential of these materials as magnetoresistive or thermal imaging sensors. The mechanisms responsible for this behaviour are complex and the subject of controversy particularly over the importance of the interaction of the electrons with the lattice that results in the formation of polarons.The reflective properties of these materials in the infra red spectral region are determined by both their electrical conductivity and the excitation of vibrational resonances; these two effects becoming convoluted in the resulting infra red spectrum. Under the application of a magnetic field, the changes in the infra red spectrum reveal the magnetic field dependence of both the electrical conductivity and other infra red active resonances. This technique, pioneered by the York research group, is called the magnetorefractive effect.We now seek to study the ultrafast dynamics, and in particular their magnetic field dependence, of both the phonon and electronic resonances in magnetic oxides. Such experiments require pump-probe techniques with a variable frequency laser such as that available at the FELIX (Free Electron Laser for Infrared eXperiments) facility at the FOM - Institute for Plasmaphysics in the Netherlands. FELIX is one of the world's premier free electron laser `user facilities' giving high power, sub picosecond pulses in the mid and far infrared. The investigators have been awarded 2 days of beamtime at FELIX via the FOM-EPSRC agreement under which users from the UK enjoy 20% of the available beamtime.This proposal is for the travel funds to enable investigators from the Universities of York and Sheffield to travel to FELIX to conduct these experiments. This will enable the York Group to learn from the expertise of the Sheffield Group in doing these experiments.The experiments will concentrate on the magnetic field dependence of resonant features in the infra red spectrum of La1xBaxMn03 as a function of temperature. This resonance, discovered in preliminary experiments, was unexpectedly found to exihibit a dramatic magnetic field dependence. We also plan to search for a similar resonant feature in La1 - xSrxMnO3 which has an abundance of free electrical carriers
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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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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.york.ac.uk |