In 2013 I graduated from the University of Warwick with an MPhys. I chose to stay on to do my PhD under the supervision of Prof. Ana Sanchez which I completed in 2017 with the title "Structure and ferroelectricity at the atomic level in perovskite oxides." I am now a research fellow on the project "Ferrotoroidic structures: polar flux-closure, vortices and skyrmions" headed by Prof. Marin Alexe and Prof. Ana Sanchez.
My main work is with ferroelectric oxide thin films, particularly ABO3 perovskites such as PbZrxTi1-xO3 and BiFeO3. I use a combination of (HR)TEM, STEM and diffraction techniques (D-LACBED) in combination with computation to detect, measure and map polarisation domains. I am interested in any application of TEM in materials science and have helped published papers on other topics such as 2D materials and electrochemistry.
Software I have worked on includes:
- A routine based off Pedro Galindo's Peak Pairs algorithm to measure the local displacement between different sublattices, used to measure polarisation
- Two versions of Martin Hÿtch's Geometric Phase Analysis for measuring strains
- Strain++ - an open source, stand alone C++ program.
- A Digital Micrograph plugin using GPUs (OpenCL) to perform the computation on the microscope in real time
- clAlign, a Digital Micrograph image alignment plugin using OpenCL that can perform a straight forward cross correlation or solve an overdetermined set of equations for the displacements
- clTEM, an opensource OpenCL multislice simulation I have worked on with Adam Dyson
- CIF2XYZ, a program to take a .cif structure and make an .xyz structure for use with simulation packages
- DM Stack Builder, a digital micrograph plugin to record live data from any signal on a microscope
- Various small digital micrograph scripts to automate or speed up tasks
D-LACBED pattern from SrTiO3. Colour was added in post-processing.
ABF-STEM image of LSMO. The oxygen octahedral tilting can
be seen as the oxygen move upwards and downwards.
Multislice simulation of Si 111 CBED pattern for increasing thickness.
- "Lateral heterojunctions within monolayer MoSe2–WSe2 semiconductors" C. Huang, S. Wu, A. M. Sanchez, J. J. P. Peters, R. Beanland, J. S. Ross, P. Rivera, W. Yao, D. H. Cobden, X. Xu, Nature Materials, 13 (2014)
- "Structural, optical and vibrational properties of self-assembled Pbn+1(Ti1−xFex)nO3n+1−δ Ruddlesden-Popper superstructures" K. I. Doig, J. J. P. Peters, S. Nawaz, D. Walker, M. Walker, M. R. Lees, R. Beanland, A. M. Sanchez, C. F. McConville, V. R. Palkar, J. Lloyd-Hughes, Scientific Reports, 5 (2015)
- "Artefacts in geometric phase analysis of compound materials" J. J. P. Peters, R. Beanland, M. Alexe, J. W. Cockburn, D. G. Revin, S. Y. Zhang, A. M. Sanchez, Ultramicroscopy, 157 (2015)
- "On the vertical stacking in semiconducting WSe2 bilayers" A. M. Sanchez, J. J. P. Peters, S. Wu, C. Huang, D. Cobden, X. Xu, R. Beanland, Materials Science and Technology, 32 (2016)
- "Polarization curling and flux closures in multiferroic tunnel junctions" J. J. P. Peters, G. Apachitei, R. Beanland, M. Alexe, A. M. Sanchez, Nature Communications 7 (2016)
- "Atomic Defects and Doping of Monolayer NbSe2" L. Nguyen, H.-P. Komsa, E. Khestanova, R. J. Kashtiban, J. J. P. Peters, S. Lawlor, A. M. Sanchez, J. Sloan, R. V. Gorbachev, I. V. Grigorieva, A. V. Krasheninnikov, S. J. Haigh, ACS Nano 11 (2017)
- "Antiferroelectric Tunnel Junctions" G. Apachitei, J. J. P. Peters, A. M. Sanchez, D. J. Kim, M. Alexe, Advanced Electronic Materials (2017)
- "Bi-ferroic memristive properties of multiferroic tunnel junctions" Z. D. Luo, G. Apachitei, M. M. Yang, J. J. P. Peters, A. M. Sanchez, M. Alexe, Applied Physics Letters 10 (2018)
- "Tracking Metal Electrodeposition Dynamics from Nucleation and Growth of a Single Atom to a Crystalline Nanoparticle" H. E. M. Hussein, R. J. Maurer, H. Amari, J. J. P. Peters, L. Meng, R. Beanland, M. E. Newton, J. V. Macpherson, ACS Nano (2018)
- "Quantitative High-Dynamic-Range Electron Diffraction of Polar Nanodomains in Pb2ScTaO6" J. J. P. Peters, A. M. Sanchez, D. Walker, R. Whatmore, R. Beanland, Advanced Materials (2018)
- "Flexible memristors based on single-crystalline ferroelectric tunnel junctions" Z.-D. Luo, J. J. P. Peters, A. M. Sanchez, M. Alexe, ACS Applied Materials & Interfaces (2019)
- "Defect Dynamics in Self-Catalyzed III-V Semiconductor Nanowires" J. A. Gott, R. Beanland, H. A. Fonseka, J. J. P. Peters, Y. Zhang, H. Liu, A. M. Sanchez, ACS Nano Letters (2019)
- "Strain-gradient mediated local conduction in strained bismuth ferrite films" M.-M. Yang, A. N. Iqbal, J. J. P. Peters, A. M. Sanchez, M. Alexe, Nature Communications 10 (2019)
- MMC 2014 (Poster) - "Exploring the polarity in oxide thin films"
- IMC 2014 (Oral) - "Exploring the polarity in oxide thin films"
- MSM 2015 (Oral) - "Anomalous strain from geometric phase analysis of Z-contrast images at interfaces"
- MMC 2015 (Oral) - "Structure and dynamics of Pb2ScTaO6 relaxor ferroelectrics studied using transmission electron microscopy"
- MMC 2015 (Poster) - "Anomolous strain at interfaces in geometric phase analyses of Z-contrast images"
- Domain walls as new 2D functional materials 2016 (Poster) - "Domain structure in ultrathin ferroelectric tunnel junctions"
- EMAG 2016 (Oral) - "Revealing local polarisation and domain configurations in ultrathin ferroelectric tunnel junctions by annular bright field STEM"
- International Workshop on Topological Structures in Ferroic Materials 2017 (Invited talk) - "Revealing polarisation curling and flux closures in ferroelectric tunnel junctions using atomic resolution transmission electron microscopy"
- IMC19 (Poster) - "In situ transmission electron microscopy of domain switching in ferroelectric films"
- ISFM14 (Oral) - "Polarisation and octahedral tilting at La0.7Sr0.3MnO3-PbTiO3 interfaces in ferroelectric tunnel junctions"