Tailoring the Crystal Structure Toward Optimal Super Conductors

Abstract : We have studied the properties of layered transition metal compounds in search of unconventional superconductors. The aim is to identify ground states competing with superconductivity, and to use tuning parameters such as doping or pressure, to reveal the effects of this competition. The key results from the project are: -the discovery of remarkable transport properties in the doped layered dichalcogenide TiSe2, where Pt doping or Se deficiency result in a 10 order of magnitude change in the low temperature resistivity.- the synthesis and characterization of single crystals of GeBi2Te4, where the proper structural characterization revealed the non-trivial topological metal properties of this compound- the discovery of remarkably high ordering temperature (up to 300 K) in R5Pb3 compounds (R = heavy rare earth)- the discovery of enhanced itinerant magnetism in Co2As1-xPx, with the magnetic properties tuned by structural phase transitions.