Roger Johnson

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Roger Johnson

Royal Society University Research Fellow

My research interests lie in the physics of complex transition metal oxides and related compounds. These crystalline materials exhibit a broad range of exotic phenomenology that emerges from the quantum state of matter, and in some cases, they have potential for application in new solid-state technology. My current research focuses on multiferroic materials that may be used to produce new multifunctional devices in which magnetic and electric properties are coupled. I characterise the physical behaviour of new compounds via bulk electric polarisation, specific heat, and magnetisation measurements. This work is complemented by neutron and x-ray diffraction experiments at central facilities, through which I solve the microscopic crystal and magnetic structures, aided by the application group theory and Landau theory. The ultimate goal is to explain macroscopic properties relevant to technological application by a comprehensive understanding of the microscopic behaviour. I am also studying 5d transition metal compounds through state-of-the-art synchrotron x-ray diffraction experiments, which are revealing unusual magnetic structures that originate in magnetic interactions beyond the Heisenberg model.

  • Award for excellence, University of Oxford, 2017
  • BCA-IOP Physical Crystallography Prize 2014, awarded for the best recently published work by a person in the early stages of their career, working in the field of Physical Crystallography, whose research is expected to make a significant impact in the field.
  • Award for excellence, University of Oxford, 2014
  • Keith Nicholas prize, Durham University, presented on the recommendation of the Head of Department in Physics to a postgraduate student of Physics on the basis of outstanding overall performance.
  • Lecturer, 4th year Structure and Dynamics
  • Supervisor to one DPhil student
  • Co-supervisor to three DPhil students
  • Supervisor to MPhys project students
  • Tutor for the fourth year condensed matter physics option