Zahid Hussain passes his viva!

Zahid Hussain

Congratulations to PGR Zahid Hussain, who has passed his viva. His thesis was titled ‘Metal-organic Framework (MOFs) Derived Nanocomposites: Synthesis and Applications in Photocatalysis’. During his time with the CDT, Zahid published 11 papers, plus an English-to-Urdu translation of Seven Brief Lessons on Physics by Carlo Rovelli. Zahid now works as a postdoctoral researcher at Technical University of Munich (TUM).

Zahid reflects on his experience of undertaking a PhD as part of the CDT:

I believe that life is a journey from nowhere to nowhere. The pleasure of living is in the process itself, and destinations only milestones leading us to the next journey. On this path, we meet all kinds of people. While some settle down on the way, others continue to live nomadic academic lives. As a foreign student, I identify myself with migratory birds, who leave behind many relationships, friendships, cultural and sensory experiences of material and non-material things, seeking better learning and living conditions. In the quest for knowledge and professional opportunities, the continuous struggle to assimilate into a new environment provides us with great learning opportunities, which broaden our mental horizons and deepen the understanding of life indeed.

The last 4 years of my life at the University of Exeter have been full of happenings, professionally and personally. I met some wonderful people, on-campus and off-campus. Many interactions turned into enduring friendships. First of all, I got a great sense of freedom in working with my PhD supervisors Dr Yongde Xia and Prof Yanqiu Zhu, which helped me to grow as an independent researcher. Also, my supportive colleagues and friendly environment of Functional Materials Laboratory (Lab 08) made the overall PhD experience very joyful and productive.

The doctoral training program (CDT) gave me the confidence to think independently and make my own research decisions. During this time, I developed some fruitful collaborations, especially with Dr Asif Tahir (Penryn campus), Prof. Roland Fischer (TU Munich), Prof. Freek Kapteijn (TU Delft, NL) and Prof. Ovidiu Ersen (University of Strasbourg, France). The work I did in these collaborations, greatly contributed to shaping my PhD project.

Along with the PhD, the last 4 years have been the most important time of my life. I married my partner Anna-Maria and became a parent of our lovely daughter Selma as if a sailboat navigating without a compass saw the shore and anchored. Countless moments of joy, peace and contentment, as well as many sleepless nights of childcare, frustrating days, lockdown months of Covid-19 and moving back and forth from Exeter to Munich, all made this time substantial.

We wish Zahid the best of luck with his future.

Zahid has co-authored the following publications:

2021

2020

2019

2018

Selected outreach activities

Zahid has translated a book Seven Brief Lessons on Physics by Carlo Rovelli from English to Urdu. It has recently published by the Mashal Books, LahorePakistan.

Zahid has presented at the following conferences:

  • M. Z. Hussain, Y. Xia; Presentation: Bi-MOF derived nanocomposites_applications in photocatalysis, GWPore: Conference on Porous Materials for Energy, Environment and Healthcare Applications, U.K. February 2021. (2nd best presentation award) 
  • M. Z. Hussain, R. A. Fischer, Y. Zhu, Y. Xia; Poster: Making heterostructures with water: Role of temperature and water steam in MOF derived TiO2/CuOx/Cu/C nanocomposites, Euromof-20193rd International Conference on MOFs and Porous Polymers, Paris, France. October 2019.
  • M. Z. Hussain, Y. Zhu, Y. Xia; Presentation: MOF derived photocatalysts for high efficient solar-light-driven H2 evolution. MCEC 2019, Conference on Materials for Clean Energy, NPL, London, U.K.  April 2019.
  • M. Z. Hussain, R. A. Fischer, Y. Zhu, Y. Xia; Presentation: MOF derived bimetal oxide/carbon composites: Synthesis and photocatalytic applications, 6th International Conference on Multifunctional, Hybrid and Nanomaterials, Sitges, Spain, March 2019.
  • M. Z. Hussain, R. A. Fischer, Y. Zhu, Y. Xia; Poster: MOF derived TiO2/C nanocomposites for photocatalysis, ICS Winter School on Catalysis, Innovative Catalysis and Sustainability Scientific and Socio-Economic Aspects, Turin, Italy. January 2019.
  • M. Z. Hussain, Y. Zhu, Y. Xia; Poster: MOF derivatives for visible-light-driven photocatalytic applications, 41st Annual Meeting of the British Zeolite Association (BZA), Cumbria, Ambleside, U.K. July 2018.
  • M. Z. Hussain, Y. Zhu, Y. Xia; Poster: Black porous ZnO@C nanocomposites derived from MOF-5 for highly efficient photocatalytic application, RAMS-Recent Appointees in Materials Science, University of Exeter, U.K. September 2017.
  • M. Z. Hussain, Y. Zhu, Y. Xia; Poster: MOF-5 derived ZnO/C nanocomposites for adsorption and photodegradation of organic pollutants, NIM Conference on Nanostructured Functional Materials for Sustainable Energy Provision, Munich, Germany. July 2017.

Month 6 Presentation Prize Winners Announcement

This year, we have a joint win for our Month 6 Presentation Prize: congratulations to first year PGRs Joe Pitfield (also the winner of the Month 13 Presentation Prize)and Leanne Stanfield. They will be collecting their mystery prize soon…

The Month 6 presentations are given each May by first year PGRs, at the end of the six month mini project the students undertake before beginning their PhD project work. Feedback scores are given by their peers and by academic chairs (this year Dr Anna Katharina Ott and Dr Eric Hébrard took on these roles). Leanne’s presentation was titled ‘Graded negative index surface wave lens’ and Joe’s was titled ‘Structural stability of TMDC Heterostructures in the Presence of Water ’.  Please find their projects aims and methodology below.

Graded negative index surface wave lens

Leanne Stanfield

Aim:

Model, fabricate and characterise a graded negative index surface wave lens. One study has
already produced a free-space negative index gradient lens [1]. The aim here is to do this with surface
waves.

Methodology:

1. Develop Comsol modelling of microwave metasurfaces made of simple meta-atoms to give easy control of the surface wave index. Then vary the size of the individual elements to design a simple surface wave GRIN lens. This is a very demanding task using Comsol as the GRIN lens will need
modelling in its entirety. Once this task is complete the lens will be fabricated using wax-ink printing
and etching before being fully characterised using the XY microwave scanner.
2. Repeat the above with a more elaborate meta-atom, following on from the work of Tremain
et al [2], to give almost almost isotropic negative dispersion. Once again then vary the size of the
individual elements so that they allow for spatial control of the effective surface mode index. Then
combine such elements in a 2D metasurface structure to form a negative index GRIN lens. As for the
conventional lens this is a very demanding task using Comsol as again the GRIN lens will need
modelling in its entirety. The complete lens will then be fabricated using wax-ink printing and etching
before being fully characterised using the XY microwave scanner.

References

[1] Driscoll T, Basov DN, Starr AF, Rye PM, Nemat-Nasser S, Schurig D and Smith DR (2006) Applied
Physics Letters 88, 081101 ‘Free-space microwave focusing by negative-index gradient lens.’
[2] Tremain B’ Hooper I R, Sambles JR and Hibbins AP (2018) Scientific Reports 8, 7098 ‘Isotropic
Backward Waves Supported by a Spiral Array Metasurface.’

Structural stability of TMDC Heterostructures in the Presence of
Water

Joe Pitfield

Aim:

To explore the random structures and reorganisation of TMDC metamaterials in the presence of
water, with addition consideration of substrate effects.

Methodology:

First principles calculations combined with analytic Gibb’s Free energy arguments. In
addition, random structure prediction will be developed as a tool. This tool will require a sound
understanding of both physical and chemical environments and allow the prediction of new phases of
structures. It will need to be benchmarked against known phases.

References:

[1] F. Davies et al. TMDC Heterostructure band structure theory (submitted – preprint available)
[2] G. Schusteritsch et al. First-principles structure determination of interface materials: The NixInAs
nickelides, Phys. Rev. B, 2015.
[3] Heifets et al, BaZrO3, Phys. Rev. B, 75, 155431 (2007)

Elizabeth Martin wins Best Poster Award at 65th Annual Conference on Magnetism and Magnetic Materials (MMM 2020)

Elizabeth with the Best Poster Award Certificate

Congratulations to final year PGR Elizabeth Martin, who won the Best Poster Award at the 65th Annual Conference on Magnetism and Magnetic Materials (MMM 2020) (2nd-6th November 2020). This is an international conference that includes all aspects of fundamental and applied magnetism, which for the first time was held virtually. The conference had over 16000 attendees- including third year CDT PGRs Connor Sait, David Newman, Katie Lewis, Konstantinos Chatzimpaloglou and Oliver Latcham– with ~ 700 different talks and ~370 different posters as well as several different symposia, workshops, and tutorials.

One of our final year students, Elizabeth Martin, presented her research in one of the poster sessions and won a best poster award. Her poster was titled “Investigation of a Coupled Elasto-Magnetic Discs for Low Reynolds Number Pumps”. The presentation was in the format of a 90-second pitch with the poster, which could be viewed at any time throughout the conference on the conference platform, as well as an additional live Q&A session on Zoom.

The virtual format of the conference was a new experience for most of our researchers, they all enjoyed the conference and learnt a lot from the different presentations. However, they do feel that they missed the in-person experience and the chance to meet different researchers from all around the world. On the other hand, think that they have learnt some valuable skills with regards to presenting their work in an online format compared to in-person. The good news for in-person conferences is that according to our researchers their future is safe, they are just having a needed break for now.

Elizabeth says:

The virtual conference was obviously very different to that of the in-person conference, I enjoyed the experience and obviously I’m thrilled to be awarded a best poster award. I did miss the in-person experience and the chance to meet/catch-up with different researchers from all around the world, talking/messaging online is not the same, but this is the way things are at the moment. One of the benefits was that the presentations were in an “on-demand” format, meaning we were able to watch any presentation at any time we wanted because they were pre-recorded (another benefit was that this year none of us experienced jetlag).

The presentations from the conference are available to view on the conference online platform (for registered conference attendees only), until 30th November 2020. Other presenters from University of Exeter included Prof Feodor Ogrin, Elizabeth’s supervisor, and Dr Maciej Dabrowski, David Newman’s supervisor.

 

Elizabeth in avatar form at the conference’s social networking session

Month 13 Presentation Prize Winners Announcement

This year, we have a joint win for our Month 13 Presentation Prize: congratulations to second year PGRs Joe Pitfield and Will Borrows. The prize was a £50 voucher.

The Month 13 presentations are given each October, where the PGRs give a presentation on their work to date and feedback scores are given by their peers. Joe’s presentation was titled ‘The search for new materials’ and Will’s was titled ‘Simulating heat flow in thermoacoustic devices’. Please find their abstracts below.

The search for new materials

Joe Pitfield

Abstract:

It is commonly understood that there is no universal a priori approach to predicting the nature of boundary regions between materials, nor one to enable theoretical design of novel materials within such regions. We present a developing method (RAFFLE; pseudo Random Approach For Finding (Local) Energy minima) learning from existing structural prediction methods [2][1], for the pseudo-random generation of atomic structures. Materials are characterised by decomposition of both bond angle and length, with these characterisations applied retroactively to generate new structures with profiles indicative of the isolated characteristic (in these cases, Energy of formation). This method is able to predict the existence of a series of structures of known one, two and three element systems, along with other geometries known [3] to exist for chemically similar structures (for the Transition metal dichalcogenides, both H and T phase structures predicted) and multiple stable phases identical stoichiometry structures (hexagonal and tetragonal and for Carbon) along with scopes over varying stoichiometries (HCP and FCC aluminium).


References
[1] Chris J. Pickard and R. J. Needs. ‘High-Pressure Phases of Silane’. Phys. Rev. Lett.97 (4 July 2006), p. 045504.
[2] Yanchao Wang et al. ‘Crystal structure prediction via particle-swarm optimization’. Phys. Rev. B82 (9 Sept. 2010), p. 094116.
[3] Anubhav Jain et al. ‘The Materials Project: A materials genome approach to accelerating materials innovation’. APL Materials1.1 (2013), p. 011002.

Simulating heat flow in thermoacoustic devices

Will Borrows

Abstract:

The thermoacoustic effect is a process by which sound is produced by the Joule heating of a thin film (a ‘thermophone’) with an alternating current [1]. While this effect has been known for more than a century [2], recent advances in the fabrication of nano-scale films have rejuvenated the field of thermoacoustics [3,4]. Despite this, thermophones have struggled to present themselves as an alternative to more conventional piezoacoustic speakers due to their low output efficiency.
Here we present an examination into the propagation of heat within and around a thermophone through both finite-element and finite-difference simulation of a device. We do this in order to gain a greater understanding behind the thermal processes which hinder thermophone efficiency. Of particular note is the effect of the Maxwell-Cattaneo correction to Fourier’s heat law [5], which accounts for the non-instantaneous nature of heat flow. By measuring the effect of this correction on the thermal fluctuations at the boundary between the thermophone and its surrounding medium, we are able to determine a trend for this correction. Going forward, we intend to more accurately calculate the expected sound output of a thermoacoustic device, as well as quantify the effects of this correction on the thermoacoustic efficiency.
References
[1] Ding, H. Nanoscale, 2019, v.11, p.5839-5860
[2] Preece, W. H. Proceedings of the Royal Society of London, 1880
[3] Shinoda, H. et al. Nature, 1999, v.400, p.853-855
[4] Xiao, L. et al. Nano Letters, 2008, v.8, no.12, p.4539-4545
[5] Cattaneo, C. Comptes Rendus Hebdomadaires des Seances de l’Academie des Sciences, 1958, v.145, p.431-433

Month 25 Presentation Prize Winner Announcement

We are delighted to announce that third year PGR Benjamin Pearce has won the Month 25 Presentation Prize- a £50 Amazon voucher. The Month 25 presentations are given each October, where the PGRs give a presentation on their work to date and feedback scores are given by their peers. Ben’s presentation was titled ‘Mode Interference and Directional Acoustic Stop Bands in Solid-Fluid Superlattices’. Please find the abstract below.

‘Mode Interference and Directional Acoustic Stop Bands in Solid-Fluid Superlattices’

Abstract:
Whilst there is a large amount of work on one-dimensional phononic crystals (superlattices) consisting of alternating layers of solid materials, there is comparatively little investigation of the properties of the equivalent solid/fluid system. These systems are predicted to exhibit a directional transmission response not available to solid/solid systems. This response stems from an interference between the symmetric and anti-symmetric modes of a submerged plate. This effect can lead to pronounced, angularly dependent reductions in transmission, for even a single solid layer submerged in fluid [1,2]. Extending this system from a single plate to a multilayer structure offers an interesting avenue for phononic crystal design [3]. Existing work largely neglects to consider the interaction of this interference with the Bragg modes of a such a periodic structure. Here we present a numerical and theoretical consideration of the effects of this interaction and how the choice of crystal geometry offers routes for the creation of large bandwidth directional stop bands.

References:
[1] M. Seiji, “Phononic Bandgaps Pecuiar to Solid-Fluid Superlattices,” Jpn. J. Appl. Phys, 2015.
[2] Z. Sai, X. Bai-qiang and C. Wenwu, “Controlling The Angle Range in Acoustics Low-Frequency
Forbidden Transmission In Solid-Fluid Superlattice,” J. Appl. Phys, 2018.
[3] S. Zhang, Z. Y, L. Wei, G. Hu, X. Bai-qiang and C. Wenwu, “Low Frequency Forbidden Bandgap
Engineering Via A Cascade of Multiple 1D Superlattices,” J. Appl. Phys, 2018.

Applications Open: Minerva Prize PGR Colloquium

This Autumn, we will host the first student-led colloquium as part of our regular colloquia series. The idea for this first came from second year PGR Connor Sait, whilst networking at a conference. When he brought the idea back to the CDT, it evolved into giving a PhD student from outside of the CDT the opportunity to give an hour talk on their research, in the style of a normal colloquium.

Five students volunteered to be part of the organising committee (third year Emily Glover, second years Connor Sait and Katie Lewis, and first years Leanne Stanfield and James Laurenson). They have undertaken all of the planning, learning a lot about how colloquia are run in the process. Naming it the Minerva Prize, after the Roman goddess of wisdom, it was decided that any PhD student would be able to submit an abstract for an hour-long talk on their research, to be held on October 2nd at 12:30pm (BST). The winning student would also win a £250 prize.

While the original plans were to hold this special colloquium occurrence in person, it has been decided to move towards a virtual event. While this decision was made due to the current climate, we hope that this will allow more PhD students to apply regardless of geography.

How to apply:

Email a short abstract for your talk (maximum 1 page of A4) to minerva-xm2@exeter.ac.uk, as well as your institution, a contact e-mail address and where you are in your PhD. To apply, you must be a PhD student who is yet to graduate and be able to align your research to research carried out in Exeter. Students who are part of the CDT are not eligible. The submission deadline is the 28th August. We aim to announce the winner on the 4th September.

For queries, please contact minerva-xm2@exeter.ac.uk, or check out the Minerva Prize website.

 

Julia de Pineda Gutierrez wins best student paper at IEE Radio and Antenna days of the Indian Ocean Conference

Fourth year PGR Julia de Pineda Gutierrez discusses the two conferences she recently attended and their successful outcomes:

Last month, I attended two conferences, where I had the chance to present my latest research. Between the 16th and the 21st of September I took part in the 13th International congress on Artificial Materials for novel wave phenomena (also known as Metamaterials) in Rome. I was invited to present my work in a special session organized by the Physical Review Journals. After the session there was also an opportunity to meet the Physical Review editors. The session was a showcase for the work that was published in the different Physical Review Journals the year before. I was invited to present my paper on microwave edge modes that was published in Physical Review B, titled ‘Microwave edge modes on a metasurface with glide symmetry’.

The conference was a great opportunity to make new contacts and to learn about the latest work in the field of metamaterials.

The following week, I flew to Reunion Island, a French territory in the Indian Ocean, to attend the IEEE Radio and Antenna days of the Indian Ocean conference. I also gave an oral presentation, in this case titled ‘Metasurfaces for high index effective media’.

With this, I won the best student paper competition, which included a certificate and a 300€ cash prize.

Julia’s other publications include Metasurface bilayer for slow microwave surface waves’ and ‘Hexagonal symmetry metasurfaces for broadband antenna application’.

Julia presents her latest research

Prof. Bill Barnes wins the Thomas Young Prize and Medal 2019

Congratulations to Prof. Bill Barnes who has been awarded the Thomas Young Prize and Medal 2019 from the Institute of Physics. The award is made for distinguished contributions to optics, including work related to physics outside the visible region.

Bill was awarded this prize for his outstanding contributions to the development of nanophotonics, especially in plasmonics and nanoscale light-molecule interactions. He was the first to show that monomolecular organic layers (Langmuir-Blodgett layers) are optically biaxial- in doing so he established a new polarization conversion technique that became a powerful way to analyse liquid crystal materials and devices.

Bill’s present research includes developing a new all-molecular pathway to making nanophotonic materials and leading research to use confined light fields to radically alter the energy levels of ensembles of molecules. Ongoing research includes band-engineering the optical properties of carbon-based materials and manipulating the charge and energy transport of 2D molecular materials, including photosynthetic materials.

Thomas Young was an English polymath noted for having established the wave theory of light via his famous double-slit experiment, and for what is now known as Young’s modulus, which relates the stress in a body to its associated strain. He also made contributions to the theory of colour vision, first coming up with the hypothesis that our perception of colour depends on three kinds of receptors sensitive to different wavelengths of light, and to the understanding of surface tension.

All award winners will be celebrated at the Institute’s annual Awards Dinner, to be held this year on 19 November at the Royal Lancaster London Hotel, where they will be presented by the President with their medal, a prize of £1,000 and a certificate.