Superconducting and spin-dependent properties of novel materials (Tallon, Williams, Trodahl, Ruck)
We have a high-profile programme investigating high-temperature superconductors (HTS) and related materials. We focus on achieving a thermodynamic understanding of HTS by determining the pressure-, temperature-, doping- and ion-size-dependence of all the important energy and length scales pertinent to superconductivity using NMR, specific heat, Raman and muon spin relaxation. We also continue the search for novel hybrid oxide superconductors. We will determine the phase diagram and dynamic fluctuations in bulk and nanostructured perovskite ferroelectrics. These materials may be substitutes for Pb-bearing ferroelectrics (PZT, (Pb,Zr)TaO3) currently in widespread use and, more widely, they are model systems for the effects of fluctuations on a large range of ferromagnetic, ferroelectric and superconducting materials. We will study the design and growth of metal oxide semiconductors, important new materials with complex optical and electrical properties resulting from the highly polar nature of their bonding and strong internal electric fields. These are highly functional materials for semiconductor devices in UV optoelectronics, transparent electronics for solar cells and displays, high frequency/high temperature power electronics, and in nanoarchitecture due to their dramatic range of spontaneous polarisation induced nanostructures. We will use a newly-developed electrically detected ESR spectrometer to study spin-dependent recombination in organic LEDs, with the aim of identifying the radiative and non-radiative recombination centres. The first devices to be investigated will be ITO/ Pedot/ Yellow-PPV/ Ca/Al/ structures which show a bright yellow electroluminescence.