Abstract: A composition of matter for a layered ionic superconductor comprising a plurality of layers of ions and electronic interaction charges, and having a substantially improved superconducting transition temperature is described. An aspect of the composition includes a first layer comprising a plurality of alkali ions and cesium ions in particular that is adjacent to a second layer comprising a plurality of halogen ions and fluorine ions in particular. The first and second layers contain electronic interaction charges and are separated by a predetermined perpendicular distance. Crystalline structure, ionic properties, superconducting transition temperature, and superfluid density for several embodiments including companion ionic species are described and illustrated. Methods for preparing the several embodiments are provided.

Abstract: A composition of matter for a layered ionic superconductor comprising a plurality of layers of ions and electronic interaction charges, and having a substantially improved superconducting transition temperature is described. An aspect of the composition includes a first layer comprising a plurality of alkali ions and cesium ions in particular that is adjacent to a second layer comprising a plurality of halogen ions and fluorine ions in particular. The first and second layers contain electronic interaction charges and are separated by a predetermined perpendicular distance. Crystalline structure, ionic properties, superconducting transition temperature, and superfluid density for several embodiments including companion ionic species are described and illustrated. Methods for preparing the several embodiments are provided.