Dr Paul Keatley
Telephone: 01392 724170
Extension: (Streatham) 4170
I am a Post-Doctoral Research Fellow in the Electromagnetic and Acoustic Materials Group in the School of Physics and Astronomy. My primary research interests lie in the related themes of Spintronics and Magnonics for which I principally use time-resolved scanning Kerr microscopy (TRSKM),, to explore and understand high-frequency oscillatory processes of nanoscale Magnetic Materials on picosecond timescales. Recently I have combined the magneto-electronic capabilities of the Spintronics theme with TRSKM to record nanosecond movies of the magnetisation dynamics generated by a vortex spin-torque nano-oscillator in collaboration with The Royal Institue of Technology (KTH), and the University of Gothenburg, in Sweden. An understanding of how the magnetisation dynamics of STNOs can be used to effectively couple multiple oscillators built on the same magnetic layers is anticipated to be the key to developing a new generation of nanoscale microwave oscillators for applications ranging from telecommunications to biosensing.
Presently I am working on an EPSRC funded project awarded to Professor Robert J Hicken in collaboration with Queen's University Belfast to develop a plasmonic antenna for near-field magneto-optical imaging at the deep nanoscale. Specifically I have developed a platform to support such a technique by integrating an atomic force microscope (AFM) with a scanning Kerr microscope. While the development of an AFM probe tip with a plasmonic antenna is ongoing, the new platform is proving to be essential for the characterisation of fabrication advances such as focussed ion beam milling of apertures through commercially available AFM probe tips. Such developments have led to the succesful demonstration of scanning pin-hole optical microscopy in transmission using an AFM probe. The next intermediate milestone will be to demonstrate scanning near-field optical microscopy using sub-wavelength apertures before adding a plasmonic antenna to the AFM probe tip specifically for magneto-optical sensitivity in the near-field.
From 2008 to 2012 I worked as a Post-Doctoral Research Associate supported by the EPSRC grant Spin@RT and the EU FP7 grant MASTER. During that time I implemented the magneto-optical measurement of phase-resolved ferromagnetic resonance spectra from individual nanomagnets,, non-local spin transfer torque in an individual spin valve nano-pillar, and coupled domain wall dynamics in pairs of magnetic nano-wires. Immediately after my PhD I was instrumental in the development of time-resolved x-ray photo-emission electron microscopy (TR-XPEEM) and x-ray ferromagnetic resonance (XFMR) measurements, on the I06 Nanoscience beamline at the Diamond Light Source, Didcot, UK. These developments led to a new NSF-EPSRC grant with UC Berkeley for which XFMR is routinely used at Diamond and at the Advanced Light Source, Berkeley, USA.
I was awarded my PhD in 2008 for 'Time-resolved magneto-optical investigations of picosecond magnetisation dynamics in arrays of non-ellipsoidal ferromagnetic nano-elements.' During my PhD I implemented the vector-resolved detection of the static and dynamic magnetisation in the scanning Kerr microscope. This allowed in situ hysteresis loops to be acquired from microscale arrays of nanomagnets, and the precessional trajectory of the magnetisation to be mapped. Since the start of my PhD I have worked on collaborative projects with HGST, Seagate, Crown Packaging, and Unilever. My work with HGST on arrays of nanomagnets led to the first spatial mapping of collective magnonic modes in arrays of nanomagnets, while my work with Seagate led to the first mapping of flux beaming in hard disk writers. During the project with Crown in 2012, I developed and successfully demonstrated a ferrite based radio frequency security tag which resulted in a patent application, an Invitation to meet the UK Government Science Minister, and subsequent research on similar prototypes for Unilever.
Education and Employment
- 2013 - Research Fellow, University of Exeter
- 2008 - 2013 Associate Research Fellow, University of Exeter
- 2004 - 2008 PhD Physics, University of Exeter
- 1999 - 2003 MPhys Hons Physics, University of Exeter
I have 43 peer reviewed publications and have a h-index of 13 (Web of Science).
I have a patent application for a 'Radio frequency detectable device' resulting from my work with Crown Technologies.
Invited talks and seminars presented by myself.
'Bottom up magnonics: Spin waves in isolated nanomagnets' P.S. Keatley, 2nd International Advanced School on Magnonics, June 2016, University of Exeter, UK.
'Direct observation of magnetization dynamics generated by spin-torque vortex oscillators' P.S. Keatley, MOSAIC Workshop, June 2016, Kusthotell, Varberg, Sweden.
'Magnetisation dynamics at the nanoscale' P.S. Keatley, CDT Bi-monthly meeting, November 2015, University of Exeter, UK.
'Time-resolved scanning Kerr microscopy of magnetisation dynamics at the nanoscale' P.S. Keatley and R.J. Hicken, Condensed Matter Seminar Series, April 2015, University of Leeds, UK.
'Time-resolved scanning Kerr microscopy of magnetisation dynamics at the nanoscale' P.S. Keatley and R.J. Hicken, Durham UK - India Workshop on Magnetisation Processes, March 2015, Durham University, UK.
'Magnetisation dynamics at the nanoscale' P.S. Keatley and R.J. Hicken, Nanosurf Seminar, February 2015, Nanosurf, Liestal, Switzerland.
'High frequency magneto-optical measurements' R.J. Hicken and P.S. Keatley, Institute of Physics Postgraduate Magnetism Techniques Workshop, December 2014, University of York, UK.
'Time-resolved scanning Kerr microscopy of magnetisation dynamics at the nanoscale' P.S. Keatley and R.J. Hicken, Symposium on 'Frontiers of magnetisation dynamics at the nanoscale' at the 59th Annual Magnetism and Magnetic Materials Conference, November 2014, Honolulu, Hawaii, USA.
'Time-resolved scanning Kerr microscopy: Application to Spintronic studies in Graphene' P.S. Keatley and R.J. Hicken, Quantum Systems and Nanomaterials Group Seminar, April 2012, University of Exeter, UK.
'Dynamic dipolar coupling of edge modes in a pair of nanoscale ferromagnetic discs' P.S. Keatley, P. Gangmei, M. Dvornik, R.J. Hicken, J. Grollier and C. Ulysse, Spin Master Voice Workshop, December 2011, Chateau de Villiers-le-Mahieu, France.
'Time resolved magneto-optical imaging of spin waves in magnonic meta-materials: Current status and novel opportunities' P.S. Keatley, P. Gangmei, M.K. Marcham, V.V. Kruglyak, A. Neudert, and R.J. Hicken, MAGNONICS kick-off meeting, September 2009, University of Exeter, UK.
'Precessional magnetization dynamics in ultrathin magnetic nano-elements' P.S. Keatley, V.V. Kruglyak, A. Neudert, R.J. Hicken, J.R. Childress, and J.A. Katine, Third meeting of NEDO International joint research, September 2007, Wiesbaden, Germany.
Contributed talks and posters
I have also given 21 contributed talks in the USA, Europe, Asia, and the UK, in addition to 10 poster presentations in the USA, Europe, and the UK.
Contributions to the Community
I was co-organiser and co-chair of the 'Early Career Researcher Symposium,' chair of the oral session on 'Spin Waves, Magnonics and Dynamics I,' and chair of 'Flash Poster Session II' at the 8th Joint European Magnetism Symposia (JEMS), August 2016, Glasgow, UK.
I was chair of the oral session on 'Graded Index Magnonics' at the 2nd International Advanced School on Magnonics, June 2016, University of Exeter, UK.
I was an assessor for one of the Best Student Presentation Awards at the 13th Joint MMM-Intermag Conference, January 2016, San Diego, California, USA.
I was a co-organiser of the international workshop on 'Optical polarisation conversion at the near field' hosted by the School of Physics and Astronomy, July 2015, University of Exeter, UK.
I was chair of the oral session on 'Magnonics' at the 59th Annual Magnetism and Magnetic Materials Conference, November 2014, Honolulu, Hawaii, USA.
I have reviewed manuscripts for Physical Review Letters, Physical Review B, Physical Review Applied, Applied Physics Letters, Advanced Electronic Materials, New Journal of Physics, IEEE Transaction on Magnetics, and Nature Publishing Group Asia Materials and Scientific Reports. Sine 2009 I have reviewed 19 manuscripts.
'Smaller and faster: Magnets for data storage' Four short talks with experimental demonstration given to A-level students attending the Pre-University Physics Course (PUPC), July 2015, University of Exeter, UK.
'Smaller and faster: Magnets for data storage' A seminar with experimental demonstration given to A-level students attending the Pre-University Physics Course (PUPC), July 2014, University of Exeter, UK.
'Smaller and faster: Magnets for data storage' An informal seminar to the public at the Sidmouth Cafe Scientifique, Costa Coffee, May 2014, Sidmouth, UK.
'From hard-disk to healthcare: What can spintronics do for you?' Public presentation by members of the Spin@RT consortium at The Royal Society Summer Science Exhibition 2008 by University of Leeds, Durham University, University of Warwick, University of Glasgow, and University of Exeter, June 2008, The Royal Society, London, UK.
'Data storage and ultrafast magnetization dynamics in thin film magnetic materials' P.S. Keatley and R.J. Hicken, Public poster presentation at the British Association Festival of Science, September 2004, University of Exeter, UK