Is Tl2Ni3S2 a mixed valent compound? Crystal and electronic structure investigations

Jim Lehrer on a screen set up on Squarehttps://egrove.olemiss.edu/debate_photo/1301/thumbnail.jp

The magnetoelectric effect across scales

Magnetoelectric coupling can arise in intrinsic multiferroics as well as composites. We will outline how for intrinsic BiFeO3 nanoparticles yield different magnetoelectric properties at room temperature than larger grains or bulk material. Magnetoelectric nanoscale composites of BaTiO3 and CoFe2O4 display rather poor magnetoelectric coupling macroscopically. Their micron scale counterparts on the other hand yield nice macroscopic response. The mechanical, electrical, and magnetic effects are analyzed using techniques including Mössbauer spectroscopy, magnetic force microscopy, piezoforce microscopy, and macroscopic techniques. It will be shown that microscopic coupling is strong also for (partly) conducting magnetic inclusions and nanosystems while macroscopic properties are highly dependent on good insulation of the samples. Experimental asymmetries in determining the magnetoelectric coupling coefficient are discussed. Support via FP7 Marie Curie Initial Training Network *Nanomotion* (grant n∘ 290158) & Forschergruppe 1509 are acknowledged

Hysteresis-Free Lead-Free Double-Perovskite Solar Cells by Interface Engineering

Hybrid perovskite solar cells have been creating considerable excitement in the photovoltaic community. However, they still rely on toxic elements, which impose severe limits on their commercialization. Lead-free double hybrid perovskites in the form of Cs₂AgBiBr₆ have been shown to be a promising nontoxic and highly stable alternative. Nevertheless, device development is still in its infancy, and performance is affected by severe hysteresis. Here we realize for the first time hysteresis-free mesoporous double-perovskite solar cells with no <i>s</i>-shape in the device characteristic and increased device open-circuit voltage. This has been realized by fine-tuning the material deposition parameters, enabling the growth of a highly uniform and compact Cs₂AgBiBr₆, and by engineering the device interfaces by screening different molecular and polymeric hole-transporting materials. Our work represents a crucial step forward in lead-free double perovskites with significant potential for closing the gap for their market uptake

The social consequences of the denied access to housing for refugees in urban settings: the case of Turin, Italy

The paper focuses on the access to housing of refugees, considering it an essential step on the integration path and a precondition for the full enjoyment of social and civil rights as well as social services. In Western countries, refugees mostly live in urban settings and local authorities' actions and decisions play a relevant role in shaping opportunities and obstacles for social inclusion. Lack of, or deficiencies in housing policies can result in challenging situations, jeopardising this path. The paper investigates the obstacles local authorities create through both informal practices and administrative provisions. The analysis highlights a gap between the national legal framework and its local implementation that creates major disruptions in the integration path. The paper takes the city of Turin (Italy) as a case study. A multi-method study was carried out to investigate these issues in the period between November 2007 and July 2013. In the case of Turin, within a scenario characterised by a huge absence of systematic policies supporting refugees' access to housing, many refugees have opted for squatting. While underlining refugees' agency, these experiences appear unable to properly tackle their housing needs and to achieve the objectives of social recognition and public solidarity