Relatore: Stephen Blundell - Department of Physics, Oxford UniversityLuogo: Aula Newton - Plesso FisicoE-mail organizzatore: raffaella.burioni@fis.unipr.it Stephen Blundell is Professor of Physics at Oxford University, Fellow ofManfield College and past Head of Condensed Matter at Clarendon.He is coauthor of over three hundred papers and several best seller books,including undergraduate textbooks Concepts in Thermal Physics, Magnetismin Condensed Matter, Quantum Field Theory for the Gifted Amateur, plus twoeasy-to-read booklets for a more general audience: A Very ShortIntroduction to Magnetism, and A Very Short Introduction toSuperconductivity, all by Oxford University Press. Quoting from theContemporary Physics review of the VSI to Magnetism, This quite amazingbook covers practically everything there is to know about magnetism, …,written in a relaxed, engaging, easy-to-follow style, which the authormaintains throughout.Prof. Blundell's research is concerned with using muon-spin rotation andmagnetoresistance techniques to study a range of organic and inorganicmaterials, particularly those showing interesting magnetic,superconducting, or dynamical properties. He is a very brilliant lecturerwho knows how to combine rigour, wit and accessibility to a vast audience. Abstract:Molecular groups can now be intercalated into iron-based superconductors with dramaticconsequences on the superconducting properties. These species act as charge reservoirs, sources of electricalpolarization, and also make subtle structural modifications to superconducting layers, all of which can makenovel adjustments to the band structure that in turn can control superconducting properties. By synthesizingthe compound Lix(NH2)y(NH3)1−yFe2Se2 (x ~ 0.6; y ~ 0.2), in which lithium ions, lithium amide andammonia (NH3) act as the spacer layer between FeSe layers, we have turned a 9 K superconductor into a 43K superconductor. Further chemical modification allow us to produce a range of new superconductingmaterials which we have studied using a variety of techniques including muon-spin rotation. Recently, wehave used hydrothermal reactions to produce layered lithium iron selenide hydroxides with chemical formulaLi1–xFex(OH)Fe1–ySe and thereby producing compounds whose transition temperature can be tuned fromzero up to about 40 K. Minimizing the concentration of iron vacancies in the iron selenide layer andsimultaneously increasing the electron count on iron in the selenide layers enhance the superconductingproperties in this family. Future prospects for new superconducting materials using these novel syntheticroutes will be discussed, as will also our current understanding of the superconductivity in these materials.