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Research Fellows Directory

Roger Johnson

Dr Roger Johnson

Research Fellow


University of Oxford

Research summary

Advances in technology often arise from the development of new functional materials, which typically begins with fundamental discoveries in solid-state physics. At the forefront of solid-state physics today is the study of multiferroics; materials in which both magnetic and electric properties exist, and are coupled such that an electric field may be used to switch magnetism, and vice versa. Most materials do not support such coupling, and multiferroicity arises in only a few cases as a result of complex material symmetries and compositions. These materials have attracted great interest from scientists owing to the exotic fundamental physics they display, and a huge potential for technological application in, for example, electrically written highly efficient and high density magnetic memory devices. Physical theories of fundamental electron-electron interactions that underpin most multiferroic phenomena have only recently been established. We must now understand the physics of switching multiferroics at length scales pertinent to the development of technology, where materials incorporated into devices are interfaced over micron to nanometre distances, not at the atomic scale. Through my research I will observe, manipulate, and understand the magnetic and electric domain structures of state-of-the-art multiferroic materials at practical (a few hundredths of a millimetre) length scales, in order to develop paradigms for repeatable and efficient multiferroic switching and contribute fundamental concepts to research into functional strongly-correlated-electron systems. The stage will then be set for the construction of a real prototype multiferroic device that will pave the way for advances in information technology.

Grants awarded

Domain Switching in Multifunctional Materials: Towards a Multiferroic Memory

Scheme: University Research Fellowship

Dates: Jan 2016 - Dec 2020

Value: £505,067.80