Novel magnetic excitations in complex electronic materials
Lead Research Organisation:
University of Oxford
Department Name: Oxford Physics
Abstract
This project is concerned with the investigation of a class of magnetic materials which show dramatic physical properties that could be useful in future electronic applications such as data storage. For instance, the application of a magnetic field to some manganese oxide compounds can change the state of the material from an insulator to a metal. This and other recently discovered phenomena can be traced back to collective behaviour of the electrons in the material: the electrons organise themselves so that a small external stimulus can produce a large response.There are still many unanswered questions about the microscopic mechanisms behind collective phenomena in magnetic materials, and one of the most direct ways of tackling these problems is to investigate the atomic-scale dynamics by neutron spectroscopy. In this project we will exploit new techniques and instrumentation for time-of-flight neutron scattering with position-sensitive detectors at the ISIS Facility. This proposal is timed to coincide with the completion of the MERLIN and LET spectrometers, the latter on the new ISIS-TS2 facility. The ability of these instruments to measure complete maps of spin excitation spectra will make possible experiments that cannot be done at present, so there is an exciting opportunity in the next few years to make significant advances in the field.The award will provide a project student with a thorough grounding in experimental techniques to investigate interacting-electron phenomena and will train the student in the necessary skills and knowledge required to become a next generation user of neutron scattering facilities.
Publications
Johnstone G
(2012)
Magnetic structure of DyMn 2 O 5 determined by resonant x-ray scattering
in Physical Review B
Johnstone GE
(2012)
Ground state in a half-doped manganite distinguished by neutron spectroscopy.
in Physical review letters
Description | We performed experiments which conclusively ruled out the existence of Zener polarons in a half-doped manganate, and supported a model of zig-zag antiferromagnetic chains. This system is a "fruit fly" for studies of charge order in layered materials. We also refined the magnetic order of a multiferroic material DyMn2O5 which has a large magnetically-driven ferroelectric polarization. |
Exploitation Route | Further experimental work and theoretical calculations. |
Sectors | Other |
URL | https://groups.physics.ox.ac.uk/Boothroyd/Antiferromagnets.htm |
Description | A state-of-the-art optical floating-zone furnace for crystal growth at high pressures |
Amount | £893,916 (GBP) |
Funding ID | EP/R024278/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 03/2018 |
End | 09/2020 |
Description | European Union Framework 7 |
Amount | £212,000 (GBP) |
Funding ID | Multi-Func-Materials |
Organisation | European Commission |
Department | Seventh Framework Programme (FP7) |
Sector | Public |
Country | European Union (EU) |
Start | 06/2009 |
End | 06/2011 |
Description | Single crystal spectroscopy at ISIS |
Organisation | Science and Technologies Facilities Council (STFC) |
Department | ISIS Neutron and Muon Source |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We worked together with Dr Russell Ewings and Prof Toby Perring at the ISIS Facility on the analysis of single crystal spectroscopy data. Our contribution was to perform experiments on single crystals to measure magnon dynamics, and to work on the analysis together with Dr Ewings and Prof Perring. |
Collaborator Contribution | Dr Russell Ewings and Prof Toby Perring developed the Horace software. |
Impact | The Horace software is now available to all users at the ISIS Facility. |
Start Year | 2010 |