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Ferroelectric domain walls are quasi-2D systems that show great promise for the development of nonvolatile memory, memristor technology, and electronic components with ultrasmall feature size. Electric fields, for example, can change the domain wall orientation relative to the spontaneous polarization and switch between resistive and conductive states, controlling the electrical current. Being embedded in a 3D material, however, the domain walls are not perfectly flat and can form networks, which leads to complex physical structures. In this work, the importance of the nanoscale structure for the emergent transport properties is demonstrated, studying electronic conduction in the 3D network of neutral and charged domain walls in ErMnO3 . By combining tomographic microscopy techniques and finite element modeling, the contribution of domain walls within the bulk is clarified and the significance of curvature effects for the local conduction is shown down to the nanoscale. The findings provide insights into the propagation of electrical currents in domain wall networks, reveal additional degrees of freedom for their control, and provide quantitative guidelines for the design of domain-wall-based technology.

The paper presents the theoretical framework for the use of role-playing games (RPG) to foster and motivate ecoliteracy. First, we discuss previous work on the uses of RPGs in relation to environmental education. Then we introduce the practice theoretical perspective grounding our approach. This is followed by a brief consideration of theories of motivation, as we seek to leverage this drive through playful and co-creative processes via the use of an open-ended RPG. Finally, we lay out the principles guiding our work, followed by some reflections of the results of the first pilot-test of the game.

Focused ion beam (FIB) and scanning electron microscopy (SEM) are used to reversibly switch improper ferroelectric domains in the hexagonal manganite ErMnO3. Surface charging is achieved by local ion (positive charging) and electron (positive and negative charging) irradiation, which allows controlled polarization switching without the need for electrical contacts. Polarization cycling reveals that the domain walls tend to return to the equilibrium configuration obtained in the as-grown state. The response of sub-surface domains is studied by FIB cross-sectioning, enabling imaging in the direction perpendicular to the applied electric field. The results clarify how the polarization reversal in hexagonal manganites progresses at the level of domains, resolving both domain wall movements and the nucleation and growth of new domains. Our FIB-SEM based switching approach is applicable to all ferroelectrics where a sufficiently large electric field can be built up via surface charging, facilitating contact-free high-resolution studies of the domain and domain wall response to electric fields in 3D.

This interpretative literature review discusses research published between 2000 and 2015 that focuses on the media representation of older adults. The key objective is to offer a critical discussion on the knowledge and assumptions underlying such studies. Specifically, the review examines how old age and media, respectively, are conceptualised in the research and the consequence this has for further research in the fields of ageing and media studies. The main finding from this review is that a large part of the research appears to say nothing about what old age and media are, as it either entirely fails to discuss what is meant by these terms or relies on common sense notions. The review concludes that research on older age and media suffers from a lack of dialogue over disciplinary borders and that this issue needs to be remedied. Likewise, for research to move on, it is imperative to take a more reflexive stance on the topics in order to avoid simplistic notions of both ageing and media.