are special iron minerals that form in oxygen- poor environments, where they influence the mobility of contaminants such as arsenic. At ID24 and BM23, Rosa et al. have determined the incorporation mechanism of noble gases at the extreme pressure temperature conditions of the deep Earth interior (page 21). At ID27, Morard et al. have investigated the properties of silica, a fundamental component of the Earth s mantle (page 23). In the field of chemistry, C. Negri et al. have resolved the structure of mobile dicopper complexes in Cu-zeolite catalysts using XAS and ultraviolet-visible (UV-Vis) spectroscopy at BM23 (page 25). M. Bykov et al. have studied the ultrahigh-pressure chemistry of nitrogen at ID15B using in-situ single crystal XRD (page 27). Finally, three examples conducted in the fields of physics and materials science are presented: at ID18, G. Cucinotta et al. have characterised the temperature effects on the charge transport properties of a spin crossover-based device (page 28). By performing complementary experiments at ID15B and ID27, J.A. Queyroux et al. have discovered a superionic bcc form of ice (page 30). Finally, at ID27, L. Henry et al. have evidenced a liquid liquid transition and critical point in sulfur (page 32).

This selection of highlights shows the dynamism of the Matter at Extremes group in a diversity of research fields. This will certainly be an advantage to explore the great opportunities offered by EBS.

M. MEZOUAR

MATTER AT EXTREMES