The University of Sheffield
Department of Materials Science and Engineering

Dr Dan A Allwood

Dr D A Allwood

BSc PhD MInstP CPhys
EPSRC Advanced Research Fellow

Address:
Department of Materials Science and Engineering
Sir Robert Hadfield Building
Mappin Street, Sheffield, S1 3JD

Telephone: +44 (0) 114 222 5938
Fax: +44 (0) 114 222 5943

Email: d.allwood@sheffield.ac.uk

Dan Allwood was awarded an EPSRC Advanced Research Fellowship in 2004 entitled `Domain wall dynamics and interactions in magnetic nanowire networks´ and in 2005 joined the Sheffield Centre for Advanced Magnetic Materials and Devices in the Department of Materials Science and Engineering. Previously, Dr Allwood worked in the University of Durham developing domain wall logic in magnetic nanowires. BSc and PhD awarded from the University of Hull, 1998.

Previously worked as a post-doctoral research assistant in:
University of Oxford, Department of Physics, 1997-1999.
Imperial College London, Department of Chemistry, 1999-2001.
Durham University, Department of Physics, 2001-2005.

Research interests

Dan Allwood´s research involves the understanding, analysis and application of magnetisation processes in magnetic thin films and nanostructures. A particular area of expertise is in domain wall processes in patterned magnetic nanowires. The extended geometry of these wires creates a simplified magnetic environment in which domain walls can be positioned. These nanowire systems have applications in information storage, information processing, sensors and biomagnetism.

Dr Allwood´s work has included the development of 2-D magnetic nanowire networks for controlling magnetic domain wall propagation. As part of this, he introduced magnetic domain wall logic in nanowire circuits, performed the first measurements of domain wall velocity in single layer nanowires and demonstrated domain wall propagation due to spin-polarised currents. Dr Allwood has developed a high sensitivity magneto-optical Kerr effect (MOKE) instrument for analysing individual nanostructures. He has also worked on optical methods to improve the MOKE response to isolated magnetic elements.

The magnetic films Dr Allwood works on are deposited on atomically-flat substrates using thermal evaporation or sputter deposition. Nanostructures are patterned either by electron-beam lithography or focussed ion beam milling. Topographic imaging of the structures usually requires either atomic force or scanning electron microscopies. The majority of Dr Allwood´s experimental research has used the MOKE technique to analyse the magnetic response of nanostructures and films. Recently, this has been complemented with studies using magnetically-resolving soft X-ray microscopy (with Dr Peter Fischer of the Advanced Light Source) and micromagnetic finite element modelling (with Professor Thomas Schrefl, University of Sheffield).

A range of projects have emerged recently in which Dr Allwood is using the stray magnetic field from patterned magnetic structures to control another system. This includes using domain walls in nanowires to trap and transport laser-cooled atoms (in collaboration with Durham University). Our calculations show that the atoms will be trapped exceptionally strongly and have very long spin coherence lifetimes. This offers a potential route to scalable quantum information processing. The stray field from simple magnetic elements is also being used to pattern biological Schwann cells to investigate growth of tissue for nerve repair.

Key projects

Professional activities and recognition

Key publications

Research group

PDRAs:
Dr Matthew Bryan
Dr Jill Weaver
Dr Isaac Luxmoore

PhD Students:
Mr Matthew Bryan
Mr Swaraj Basu
Mr Simon Bance

Research centres

Sheffield Centre for Advanced Magnetic Materials and Devices