Titre : Discovering new iron silicide compounds: A quest for superconductivity
Institut Néel, Salle F418 (Erwin Bertaut)
Résumé : The iron-based superconductors have been firmly established as an important branch of high temperature superconductivity research [1]. These materials have multi-band quasi 2D electronic structures owing to their crystal structures consisting of square planar iron sheets, with each iron atom coordinated by out of plane atoms, X, where X is most often Se or As. The strong nesting associated with the Fermiology of these materials give rise to a spin-density wave which can be destroyed by doping, revealing a superconducting ground state [2].
Recently the discovery of superconductivity in LaFeSiH motivated the search for other FeSi-based superconductors, to expand the family of iron-based superconductors beyond the chalcogenides and pnictides that usually coordinate to iron [3]. This is interesting, not only since it is one of few non-toxic iron-based superconductors, but also due to the raised prospects of finding more FeSi-based materials, hosting superconductivity.
In this talk we will explore the synthesis of new Fe-Si based materials, using a topotactical intercalation approach to modify the structure and properties of the intermetallic compound LaFeSi. We will then discuss the structure and properties of these novel compounds in context of the Fe-As compounds.
[1] H. Hosono et al. Journal of the Physical Society of Japan 89, 051006 (2020)
