Professor Dan A Allwoodallwood.jpg

BSc PhD MInstP CPhys
Professor in Materials Physics

Telephone: +44 (0) 114 222 5938
Fax: +44 (0) 114 222 5943
Email: d.allwood@sheffield.ac.uk

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

Dan Allwood was awarded an EPSRC Advanced Research Fellowship in 2004 and in 2005 joined the Sheffield Centre for Advanced Magnetic Materials and Devices in the Department of Materials Science and Engineering. His BSc (1994) and PhD (1998) in Applied Physics were awarded from the University of Hull. He also 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 focuses on 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 technology (memory and data processing) and in controlling secondary systems (e.g. magnetic beads or ultra-cold atoms).

Prof Allwood has developed 2-D magnetic nanowire networks for controlling magnetic domain wall propagation and creating new ways of performing memory and logic operations. More recently, he has introduced a hybrid multi-ferroic system for controlling domain wall position using applied stress that is suitable for synchronous memories. Dr Allwood has developed a high sensitivity magneto-optical Kerr effect (MOKE) instrument for analysing individual nanostructures and optical methods for improving the MOKE response. Dr Allwood’s work on using domain walls in nanowires as nanoscale sources of magnetic field has resulted in demonstrations of interactions with other domain walls, magnetically labelled biological cells and sub-milliKelvin paramagnetic atoms.

The magnetic films 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. Dr Allwood´s experimental research often uses the MOKE technique to analyse the magnetic response of nanostructures and films, magnetically-resolving soft X-ray microscopy (with Dr Peter Fischer of the Centre for X-ray Optics) and micromagnetic finite element modelling.

Research group

PDRAs:
Dr René Dost (Organic spintronics)

PhD Students:
Matthew Hodges (Organic photophysics)
James Wheelwright (Stress effects in magnetic nanostructures)
Madalina Negoita (Domain wall interations with cold atoms) 
Ruth Bradley (Domain wall interactions with cold atoms)
Placide Fundi (Stress effects in magnetic thin films)
Khalid Omari (Domain wall dynamics in magnetic nanowires)
Saud Al Garni (Organic spintronics)
Thomas Broomhall (Temperature-dependent magnetism)
Ahssad Fiaz (Rapid manufacturing of magnetic structures)

Project students:
Yu Zhang (Modelling of thermal insulation)
Sean Taylor (3D printing of chocolate)
Lucy Varman (3D printing of chocolate)
Meg Orloff (3D printing of chocolate)

Media and public engagement

Dan is actively involved in public outreach, particularly with school age students.

He worked with Dr Julian Dean and Dr Matthew Bryan to allow local Sixth Form students to conduct research on designing new magnetic hard drive materials. This resulted in a research paper [J. Appl. Phys. 106, (20009) 053902; doi:http://dx.doi.org/10.1063/1.3211324] and an education paper on the project itself [Phys. Ed. 44 (2009) 627; http://iopscience.iop.org/0031-9120/44/6/010]. Dan was also co-awarded the 2009 Kroto Prize for Excellence in the Science Education of Young People. Dan has also made an online presentation to explain some of his research of magnetism in cell biology (http://www.geokri.org/viewPresentation.php?id=179).

Dan has run hands-on Materials outreach activities for school students from 5 – 18. These sessions include ‘How to build an aeroplane’ (Ages 5-6), ‘Magnets’ (Ages 7-11) and ‘Structural materials properties’ (Ages 14-18).

Dan has recently worked with Dr Julian Dean to develop a suite of Flash-based virtual experiments to support Physics A-level tuition (www.flashyscience.com). These have been used to deliver lessons to A-level (16-18 years) students and are used as part of graduate programmes.

Professional activities and recognition

  • Member of the EPSRC Materials Peer Review College.
  • Member of the Editorial Board of the Journal of Physics D – Applied Physics.
  • Member of the Editorial Board of the Journal of Materials Science: Materials in Electronics.
  • Chair of the UK & RI Chapter of the IEEE Magnetics Society.
  • Member of the Institute of Physics Magnetism Group Committee.

Selected recent publications

  • M. T. Bryan, K. H. Smith, M. E. Real, P. W. Fry, P. Fischer, M.-Y. Im, T. Schrefl, D. A. Allwood and J. W. Haycock, ‘Switchable cell trapping using superparamagnetic beads’, IEEE Magn. Lett. 1 (2010) 1500104.
  • T. J. Hayward, M. T. Bryan, P. W. Fry, P. M. Fundi, M. R. J. Gibbs, D. A. Allwood, M.-Y. Im and P. Fischer, ‘Direct imaging of domain-wall interactions in Ni80Fe20 planar nanowires’, Phys. Rev. B 81 (2010) 020410(R).
  • J. Dean, M. T. Bryan, T. Schrefl and D. A. Allwood, ‘Stress-based control of magnetic nanowire domain walls in artificial multiferroic systems’, J. Appl. Phys. 109 (2011) 023915.
  • M. Negoita, T. J. Hayward and D. A. Allwood, ‘Controlling domain walls velocities in ferromagnetic ring-shaped nanowires’, Appl. Phys. Lett. 100 (2012) 072405.
  • G. Hrkac, J. Dean and D. Allwood, ‘Nanowire spintronics for storage class memories and logic’, Phil. Trans. R. Soc. A 369 (2011) 3214.
  • A. D. West, K. J. Weatherill, T. J. Hayward, P. W. Fry, T. Schrefl, M. R. J. Gibbs, C. S. Adams, D. A. Allwood and I. G. Hughes, ‘Realization of the Manipulation of Ultracold Atoms with a Reconfigurable Nanomagnetic System of Domain Walls’, Nanoletters 12 (2012) 4065.
  • M. T. Bryan, T. Schrefl, D. Atkinson, and D. A. Allwood, ‘Magnetic domain wall propagation in nanowires under transverse magnetic fields’, J. Appl. Phys. 103 (2008) 073906.
  • L. Lin, Y. Xu, S. Zhang, I. M. Ross, A. C. M. Ong and D. A. Allwood, ‘Fabrication of luminescent monolayered tungsten dichalcogenides quantum dots with giant spin-valley coupling’, ACS Nano 7 (2013) 8214.
  • H. AlQahtani, M. T. Bryan, T. J. Hayward, M. P. Hodges, M.-Y. Im, P. Fischer, M. Grell and D. A. Allwood, ‘Planar organic spin valves using nanostructured Ni80Fe20 magnetic contacts’, Org. Electron. 15 (2014) 276.
  • L. Lin, Y. Xu, S. Zhang, I. M. Ross, A. C. M. Ong and Dan A. Allwood, ‘Fabrication and Luminescence of Monolayered Boron Nitride Quantum Dots’, Small 10 (2014) 60.