Domain engineering in ferroelectric and multiferroic nanostructures

FRANCE-UK,     2009-2011
Participants, FRANCE

Prof. Igor Lukyanchuk: France Coordinator (UPJV, Amiens) is the leader of the group, who actually introduced and developed the subject of domain modelling in finite-size ferroelectrics

Dr. Laurent Baudry (IEMN, Lille) is doing the analytical and numerical modelling of switching phenomena in Ferroelectrics

Dr. Laurent Lahoche (UTC, Compiegne) is working on the numerical (finite element  - PDE) modelling of domains.

Ms Anais Sene (UPJV Amiens), 1st year PhD student, working on analytical modelling of domains

Participants, UK

Dr Alina Schilling
UK coordinator (Queen's University of Belfast)  is the main experimental force behind the microscopy work done so far, and will be responsible for making the single crystal samples with FIB and observing them under the TEM.

Prof. J. F. Scott and J. M. Gregg are the group leaders at Cambridge and Belfast respectively, and will overview the work done on the UK side of the collaboration.

Dr Gustau Catalan  (University of Cambridge) is working on magnetoelectric multiferroics, rationalising the domain configuration in multiferroic nanocrystals.

Ferroelectric materials are the basis of non-volatile computer memories in which the binary units of information are stored in form of oppositely-polarized ferroelectric domains. The growing market of world High-Tech industry leaders (IBM, Fujitsu, Matsushita) in this area is estimated as $500M/year. Increasing of the information storage capacity is provided by decreasing of the sample size and, therefore, a growing body of work is dedicated to understanding the interplay between sample size, domain structure and functional behaviour in traditional thin-film ferroelectric memories. At the same time, the miniaturization of such 2d devices already reached its technological thickness limit of several unit cells and the roadmap of microelectronics-2010 requires the engineering of new generation of memory-capacitive 3d ferroelectric units for which much less is known.

 In the last two years the Partner Team from UK (Cambridge and Belfast)) has achieved remarkable progress in controlled elaboration of free-standing micro- and nanoscale samples from technological ferroelectric material – BaTiO3 and in visualization of its domain structures Meanwhile there is no satisfactory theoretical explication of the origin and behaviour of the observed domains that is very important for the controlled design of their geometry, switching and ultimate performance of the constructed device. The aim of this collaboration is to bring together the experimental expertise of the UK (Cambridge and Queens's University of Belfast) and the theoretical expertise of France (Amiens, Lille) in a joint effort to understand domains in nanoscale ferroelectrics , with an emphasis on three-dimensional structures and magnetoelectric multiferroics, which are touted as the basis for novel dual read/write memory technology.

UK laboratories in Cambridge and Belfast are world-leading experts in ferroelectric domains and nanostructures, and in the physics of ferroelectric devices. Project ACI Alliance presents the unique opportunity for young French participants to study the organization of research here. PhD students will gain first-hand access to this expertise and transform this know-how to their universities. This especially concerns the emergent group of Ferroelectric Oxides from small and young University of Amiens. Collaboration with such excellence research centre as Cambridge will substantially valorise researches in Picardy. At the same time, joint collaboration will make more visible the research, done in small French Universities outside of France.

At the same time, the more experimentally-minded work done by the British team would benefit enormously from collaborating with the first-class theoretical expertise of the French collaborators. Not only their feedback and guidance will be central to the success of the experimental work, but, their mentoring will also be invaluable for establishing our own finite-element calculation facility, which we can then apply autonomously to other problems. In the long run, establishing of a solid channel of communication between groups competent on the experiment and applications of ferroelectrics (UK) and their theory and simulations (France) can only be beneficial for both.

Parenthetically, we note also that a relevant aspect of the project is the good geographical connectivity of the participants. All the partners (except Belfast) are located within 300km in a railway connection which reinforces the European Regional inter-Channel links France-UK. Belfast itself has several daily flights to both Stansted (30 min from Cambridge) and Paris, and has so far maintained a very fluid exchange of people in its long term collaboration with Cambridge. Just as importantly, if not more so, the personal relationship between the participants is excellent, both within and between the two countries, which means that both sides will enjoy working together for the success of this project, thereby enhancing its chances of success.