Visiting Researcher Support for Prof Nagarajan Valanoor (University of New South Wales)

Lead Research Organisation: Queen's University of Belfast
Department Name: Sch of Mathematics and Physics

Abstract

This proposal seeks funding to support Professor Nagarajan Valanoor to spend 3 months (October-December 2010) as a visiting researcher in Queen's University Belfast, and work in collaboration with Professor JM Gregg's nanoscale ferroelectrics activity.Prof Nagarajan is acknowledged internationally as an expert in nanoscale ferroelectrics, with particular expertise in thin film growth, nanoscale patterning and domain imaging using piezo-force microscopy (PFM). His knowledge, experience and interests are strongly aligned with those of the nanoscale ferroelectrics group in Queen's University Belfast (QUB), and his stay in QUB should be extremely useful both in terms of helping to accelerate progress in ongoing research, and in terms of performing preliminary work for potential future collaborative programmes. During his visit, we wish to pursue three themes of common interest:(i) PFM imaging of domain configurations in ferroelectric nanoshapes (contributing to a current EPSRC-funded programme: EP/F004869/1 Investigating the fabrication and dipole characteristics of complex ferroelectric nanoshapes );(ii) Modification of the PFM system at QUB to allow dynamical studies of switching in ferroelectric nanoshapes;(iii) Preliminary exploration of potential flexoelectric polarisation nanodevices.

Planned Impact

Prof Valanoor's visit will boost progress in high impact fundamental exploratory work on meso and nanoscale ferroelectrics. The ongoing work at QUB is unique in the world at the moment, and has already generated results that have had wide interest, been published in high impact general science journals (and been highlighted in 'Chemistry World' for example) and induced invitations to speak on the topic at prestigious major international conferences, with attendees from all aspects of Materials Science and Physics (MRS and APS Meetings), from academia and industry. The impact of the work is strong and goes well beyond the immediate professional circle carrying out similar research. Industrialists involved in the production of devices incorporating meso and nanoscale ferroelectrics should gain from the programmes which Prof Valanoor's visit will augment. Small scale ferroelectrics are of great interest for a range of electronic, transducer and energy harvesting devices, such as non-volatile memory, dynamic memory, field-effect transistors, high charge-density capacitors, piezoelectric nanopositioning devices and ultrahigh frequency resonators; crucially these are generally not mature technologies (although FeRAM has been in production for a number of years) and industrialists therefore need to keep an eye on the advances in science produced by the academic community. Indeed, many of the international conferences in which progress on our work is presented are heavily populated by industrialists. The wider society should ultimately benefit from the research that Prof Valanoor will contribute towards. Electronic devices incorporating small scale ferroelectrics are already responsible for the memory systems used in many contactless Smart Cards, such as those used on the public transport networks in Tokyo. Games consoles, such as the PlayStation series have used ferroelectric memory devices. Equally, ultrahigh resolution inkjet printers of the future, or nanoscale vaccine injection systems might rely on controlling the domain dynamics in ferroelectric nanotubes. Improvements in technology based on improved basic understanding of ferroelectric behaviour at the nanoscale should help expand these kinds of applications, and play a part in improving the quality of life for many. To ensure that the impact of the work is maximised, the QUB team will continue to publish in high impact general journals, and continue to disseminate the work through conferences as widely as possible, and to as many different audiences as possible. We will also continue to cooperate in dialogue with industry (members of the QUB nanoscale ferroelectrics group have previously openly discussed work with Samsung in Korea, Avx Ltd., Seagate and Analog Devices in N. Ireland, and Epson in Cambridge), and we will advertise progress and key findings on our website. Chance approaches, such as that recently made by Frost and Sullivan, a company that informs research, technology and business development executives about new developments in high-tech materials which may show commercial promise, will continue to be taken. We are always aware of the potential for exploitation, and before releasing results and insights we review opportunities for patent protection of IP. This is often done in conjunction with the dedicated QUB support team involved in academic IP. To date we hold one patent resulting from our work, which is held jointly by QUB and Cambridge. Prof Valanoor's visit has great potential for enhancing collaborations between the QUB group and his own group in UNSW. Indeed, one of the reasons for the 3 month visit is to cement initial collaborative ventures, and make progress on some exploratory thin film growth and measurements which could lead to more formal funded collaboration in the future.

Publications

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Description The key outcome of this project was that Nagy Valanoor spent several months in Belfast helping with the piezoresponse force microscopy of PZN-PT single crystals and transfering his expertise. Using techniques that he shared with the research team in QUB, self-similar nested flux-closure objects were found around the edges of thin PZN-PT crystals. Results and insights were published in Nano Letters in 2013 and JAP in 2014. The relationship formed as a result of the grant has allowed ongoing low-level collaboration between QUB and UNSW, such that we now work together on FIB cutting of BiFeO3 thin films and have published a recent review together on the role of FIB in nanoscale ferroelectrics (Adv Func Mater 2017).
Exploitation Route The focus of this project was to transfer knowledge and expertise from UNSW to QUB and to perform a specific study on domains. Complex flux-closure patterns were discovered which are the precursors of ferroelectric vortices, the toroidal moment of which has been cited as a potentially revolutionary binary memory technology (but has not to date been experimentally observed). None in a commercial sense, but the project funding has allowed an ongoing research collaboration with Nagy to develop which should lead to further science and potential applications in the future.
Sectors Digital/Communication/Information Technologies (including Software),Electronics