Artificial Ferroic Systems

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Date and time 29.02.2016 13:1514:15  
Place and room
Speaker Prof. Laura Heyderman
, ETH Zürich – Paul Scherrer Institute
Category Conferences - Seminars
In artificial ferroic systems, through the combination of patterned ferroic materials and the control of the interactions between the different components, novel functionality can be engineered that is interesting for a wide variety of applications including data storage and transfer, memory, sensors and high frequency communications. I will present two classes of these systems, beginning with hybrid mesoscopic structures incorporating two different ferromagnetic layers whose static and dynamic behaviour result from the mutual imprint of the magnetic domain configurations. Here we have demonstrated a new mechanism for control of the magnetisation at the sub-20 nm scale [1], so providing a local magnetic switch.

I will then describe our progress on artificial spin ice, consisting of arrays of dipolar-coupled nanomagnets arranged in frustrated geometries. We have used synchrotron x-ray photoemission electron microscopy to observe the behaviour of emergent magnetic monopoles in an array of nanomagnets placed on the kagome lattice [2]. We have also created artificial spin ice with thermally fluctuating magnetic moments and observed the evolution of magnetic configurations with time. This has provided a means to study relaxation processes with a controlled route to the lowest-energy state [3] and we have also demonstrated with muon spin relaxation that these magnetic metamaterials can support thermodynamic phase transitions [4]. Future directions include the incorporation of novel magnetic materials, the investigation of 3D structures [8], as well as the implementation of synchrotron x-ray resonant magnetic scattering to study magnetic correlations in arrays of smaller nanomagnets at faster timescales.

[1] P. Wohlhuter et al., Nature Communications 6, 7836 (2015)
[2] E. Mengotti et al., Nature Physics 7, 68 (2011)
[3] A. Farhan et al., Nature Physics 9, 375  (2013)
[4] L. Anghinolfi et al., Nature Communications 6, 8278 (2015)
[5] C. Donnelly et al., Physical Review Letters 114, 115501 (2015)

Bio: Laura Heyderman began her career in magnetism in 1988, working as a Bristol University PhD student at the CNRS, Paris on magnetic multilayers. As a postdoc using electron microscopy at Glasgow University, she worked on a variety of magnetic materials. She then spent four years working in industry in the UK and since 1999, she has been based at the Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute. In January 2013, she became Professor of Mesoscopic Systems at the Department of Materials, ETH Zurich.
Professor Heyderman has over 137 scientific publications, most recently in the field of magnetic nanostructures. Her work on artificial ferroic systems has led to several invited and plenary talks, as well as articles in the German and French equivalents to Scientific American. She is Membership Chair as well as member of the Nomination and Advisory Committees of the IEEE Magnetics Society. She has been a program and advisory committee member of several international conferences on magnetism and was program chair of the Micro- and Nanoengineering Conference (MNE) 2014 held at the EPFL campus. She is a Fellow of the Institute of Physics and held the Wohlfarth Prize Lecture at Magnetism 2015, the UK magnetism meeting run by the Institute of Physics & IEEE Magnetics Society, and has been awarded a Beller Lectureship for the American Physical Society Meeting in March 2016.

Practical information

  • General public
  • Free

Organizer

  • Prof. Michele Ceriotti

Contact

  • Prof. Michele Ceriotti

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