| Dr D Allwood |
| 59 |
MAGNETIC NANOWIRES FOR TRAPPING LASER-COOLED ATOMS
Supervisor: Dr D Allwood |
We are seeking an enthusiastic and motivated individual to study magnetic domain walls in ferromagnetic nanowires. These will be used to trap and transport laser-cooled atoms by collaborators at Durham University as part of an EPSRC-funded research programme. We have shown how the stray magnetic field from the mobile domain walls in nanowires can be used to trap atoms [see Allwood et al, Applied Physics Letters 89, 014102 (2006)]. The current programme seeks to study this experimentally. Magnetic nanowire technology is currently an exciting research topic [see, for example, Allwood et al, Science 309, 1688 (2005)], with dozens of interested research groups and companies worldwide. This programme joins the latest advances in magnetic nanotechnology with state-of-the-art atomic physics to make a unique collaboration. As part of the Sheffield Centre for Advanced Magnetic Materials and Devices (SCAMMD), you will use electron beam lithography to fabricate ferromagnetic nanowires and a high sensitivity laser-based magnetometer to investigate the behaviour of magnetic domain walls. You will also use various forms of electron and scanning probe microscopy to characterise the nanostructures and finite element computer models to simulate domain wall processes. You will be working with other students and research staff in SCAMMD and will liaise with other project members in Durham.
The University of Sheffield, and SCAMMD in particular, has state-of-the-art facilities that will be used in this project. These include electron beam and optical lithography, several sputter and thermal evaporation systems for thin film deposition, a commercial ion miller for device fabrication, several magnetometers for characterising magnetic materials, atomic/magnetic force microscopy and several transmission and scanning electron microscopes. In addition, the Department of Engineering Materials has a computer cluster (18 nodes dual processor, dual core with 16 Gbit memory each) and access to the University’s 300 GFLOP high performance computer. |
| Professor M R J Gibb |
| 60 |
MICROSTRUCTURE AND MAGNETIC PROPERTIES OF ULTRA THIN FILMS
Professor M R J Gibbs, Dr D A Allwood and Professor W M Rainforth |
| This project will study NiFe and CoFe ultra-thin films. For use of these alloy films in devices the magnetic properties must be controlled. The microstructure/property relationships appear to be subtly different at small film thickness, but there is little published work in this area. This project will grow (thermal evaporation and sputtering) and characterise nanometre thick films. Techniques to be used include deposition, magnetometry, magnetotransport and electron and magnetic force microscopy. There may be collaboration with scientists at the Advanced Light Source at Lawrence Berkeley Labs, CA, and the Diamond Light Source, Rutherford Appleton Lab. |
| 61 |
MAGNETOSTRICTION IN THIN FILMS
Supervisors: Professor M R J Gibbs and Dr N A Morley |
| Magnetic thin films of FeCo, FeGa and amorphous Fe-based alloys will be optimised by careful control of the processing, to give optimised magnetic performance. We will be particularly looking at generating large DeltaE-effect in the films. The optimised films will be placed on MEMS cantilevers or membranes for device testing. The experimental work will be complemented with finite element modelling of the system, and the model will be used to iterate the device fabrication steps to achieve optimum system performance. |
| Professor T Schrefl |
| 62 |
COERCIVITIES AND GRAIN BOUNDARIES IN HIGH PEFORMANCE PERMANENT MAGNETS
Supervisor: Professor T Schrefl |
High performance permanent magnets are of great importance for current and future
technology. Rare-earth based permanent magnets are used in motors and generators.
High performance magnets will enhance their efficiency being especially important
for energy saving and a green environment. One rapidly growing application area of
permanent magnets are hybrid cars. Here the magnets require a high performance combined
with a high thermal stability. Within this project we will investigate the influence of
grain boundary properties on the magnetic properties of NdFeB based sintered
magnets using atomistic and finite element simulations. This is a collaborative project
with industry and other European research institutes. |
| 63 |
THREE DIMENSIONAL MAGNETIC STORAGE TECHNOLOGIES
Supervisor: Professor T Schrefl |
The current industry objective for magnetic storage is to achieve an area density
of 10Tbit/in2 within the next five years. One possible means to achieve such
high area densities is multilayer storage as currently used in DVD and optical storage.
Information is stored on multiple magnetic layers that can be addressed using a microwave
field that matches the magnetic resonance frequency of a given layer. In the project
you will design a 3D storage system based on finite element simulations of the write and read process. |
