skip to content
 

Past events hosted within or of interest to the Department are listed here (upto 1 year ago). Visit our main Events page to see upcoming events.


  • 16May

    Speaker: Professor Patrick Grant FREng, Department of Materials, Oxford University, UK.

    Since the invention of the Li ion battery more than 30 years ago, there have been steady improvements in performance such as energy and power density. However the most dramatic change has been the reduction in cost per unit energy stored due to manufacturing innovations, which have reduced costs by more than an order of magnitude. While costs continue to reduce, albeit more slowly, battery performance is beginning to stagnate. However, this plateau of performance is disappointingly well-below the intrinsic energy storage performance of the active cathode and anode materials that comprise the Li ion battery. The root of the performance plateau is the ubiquitous method of creating the electrodes, which although highly productive, constrains the range structures and performance that can be achieved. This talk explores novel ways of producing electrodes used in Li ion and Na ion that have structures that allow the intrinsic energy storage capabilities of materials to be realised more fully. For example, we have developed manufacturing techniques that provide extra control on how a polymeric binder distributes during the drying of a slurry cast Li ion battery electrode, how to eliminate organic solvents used in electrode processing, and how to mix optimally different active materials in a single electrode. By improving microstructural control, battery performance is enhanced, and the design space for battery electrode architectures and performance is widened. Because design options are increased, trial and error electrode optimisation by experiment typical of the battery industry becomes impossible. Therefore, the use of modelling and simulation becomes essential, both to understand the electrochemical behaviour of our smart hetero-electrodes and to guide the microstructural design of electrodes for a particular balance of desired properties.

    http://talks.cam.ac.uk/talk/index/216439

  • 02May

    Speaker: Young-Gwan Choi, Post-Doctoral Researcher, Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.

    The experimental observation of the orbital Hall effect (OHE) in a light metal Ti using the magneto-optical Kerr effect (MOKE) will be presented. The OHE is the generation of electron orbital angular momentum flow transverse to an external electric field, and although circumstantial evidence has been growing, direct detection has remained elusive. Previously, theoretical studies predicted that the OHE is a fundamental origin of the spin Hall effect (SHE) in many transition metals. Our experimental results confirm the existence of the OHE in a light element metal Ti with an unexpectedly long orbital relaxation length, ~70 nm. We found that the MOKE signal due to the OHE -induced orbital moment is orders of magnitude larger than that due to the spin moment induced by the SHE in Ti. Moreover, we examined the torque efficiency and the orbital relaxation length using orbital torque experiments with a ferromagnet layer. This observation challenges the belief that orbital angular momentum is quenched in solids. The presentation will also discuss the potential of using the orbital degree of freedom as an information carrier and the importance of studying the orbital degree of freedom. The findings significantly impact the electrical control of magnetism and underscore the need for an improved understanding of OHE dynamics in various materials. Moreover, this presentation will also explore further directions for OHE studies using other techniques such as nitrogen-vacancy scanning and x-ray circular dichroism.

    http://talks.cam.ac.uk/talk/index/216436

     

  • 21Mar

    Speaker: Dr Wenshuo Xu, Department of Materials Science & Metallurgy, University of Cambridge

    25 minutes plus questions unless stated otherwise (please arrive a few minutes early to start on time)

  • 16Mar

    Drop in and explore the world of materials science through our table-top displays and interactive activities. Find out how we can make electricity from colourful windows, investigate how our technology wastes energy, see a wire change shape by itself and use a microscope to look at what’s inside a piece of metal.

    Our activities are suitable for all ages, and researchers will be on hand to answer your questions! Come along and see how our world-leading science will power tomorrow’s technologies and have an impact on the world we live in.

    Suitable for ages 5yrs+.

  • 07Mar

    Speaker: James Moloney, Department of Materials Science & Metallurgy, University of Cambridge

    25 minutes plus questions unless stated otherwise (please arrive a few minutes early to start on time)

  • 22Feb

    Speaker: Dr Chiara Gattinoni, Dept. of Physics, Kings College, London

    The behaviour of nanoscale forms of matter, such as thin films or nanocrystal, is strongly influenced by the structure and behaviour of their surfaces and interfaces. In nanoscale ferroelectrics, a surface charge arises as a consequence of the ferroelectric polarization itself, and this surface charge leads to an electrostatic instability – the so-called “polar catastrophe” – if it is not compensated. Here we show how the properties of ferroelectric materials at the nanoscale are intimately linked to the compensation mechanism that takes place at their surface. We also demonstrate how the structural and electronic properties of PbTiO3, BiFeO3 and KTaO3 lead to a different compensation mechanism in each case, and we discuss how to harness the properties of these nanoscale materials for applications in microelectronics and catalysis.

    http://talks.cam.ac.uk/talk/index/211096

  • 22Feb

    Speaker: Dr Mehmet Egilmez, American University of Sharjah, UAE

    High/medium entropy alloys have attracted great scientific and industrial interest during the last two decades. In general, these alloys consist of 3 to 7 (or more) elements in large percentages, which leads to a high degree of disorder and hence a very large configurational entropy. In these alloys, the utilization of a large number of elements results in rich compositional tuning, which in turn results in exciting mechanical, electrochemical, magnetic, and electronic functionalities.  The talk will present our recent efforts on the CoNiCr(V) medium-entropy system and TiZrNbSn shape memory alloy superconductor. The CoNiCr system is particularly interesting because it possesses exceptional mechanical properties across a wide range of temperatures, excellent corrosive resistance, electrochemical functionalities, and unique transport and magnetic properties. The extraordinary properties of this system not only are due to differences in atomic radii and electronic configurations of constituent elements but are also dependent on the magnetically driven chemical short-range order.

    25 minutes plus questions unless stated otherwise (please arrive a few minutes early to start on time)

  • 08Feb

    Speaker: Dr Mengfan Guo, Department of Materials Science & Metallurgy, University of Cambridge

    25 minutes plus questions unless stated otherwise (please arrive a few minutes early to start on time)

  • 01Feb

    Speaker: Dr Lutz Kirste, Fraunhofer Institute for Applied Solid State Physics (IAF), Freiburg, Germany.

    http://talks.cam.ac.uk/talk/index/211093

  • 25Jan

    Speaker: Professor Bilge Yildiz, Massachusetts Institute of Technology, Cambridge, USA

    Abstract:

    Exsolution is an effective approach to fabricating oxide-supported metal nanoparticle (electro-)catalysts via phase precipitation out of a host oxide. A fundamental understanding and control of the exsolution kinetics are needed to engineer the size, density and composition of exsolved nanoparticles to obtain higher catalytic activity toward clean energy and fuel conversion reactions, such as in solid oxide fuel and electrolysis cells. Since oxygen release via oxygen vacancy formation in the host oxide is behind oxide reduction and metal exsolution, we hypothesize that the kinetics of metal exsolution should depend on the kinetics of oxygen release. In this work, we probe the surface exsolution kinetics both experimentally and theoretically using thin-film perovskite oxide model systems, show its relation to the oxygen evolution kinetics, and tune it by external drivers including elastic strain and ion irradiation. Using both drivers, we couple to the formation of point defects and defect clusters, that serve as nucleation sites for nanoparticle exsolution. As a result, we can controllably tune size, density, composition and position of the exsolved metal nanoparticles. This finding can guide the design of exsolution electrocatalysts to advance the performance and durability of solid oxide electrochemical cells.

    http://talks.cam.ac.uk/talk/index/211003