An Investigation of the Pressure-induced Superconductivity Transition Temperature Tc and Related Properties in Elemental Superconductors.

摘要

More than half of the elements in the periodic table, 53 out of 92, are known to be superconductors with 23 elements becoming superconductors with increased pressure [1--3]. This thesis explores the electronic-structure for a wide variety of crystal structures for several elemental materials by first-principles methods to determine the pressure-dependent electronic, structural and superconductivity transition temperature Tc properties. Elements that have been investigated are scandium, lanthanum, europium, and phosphorus. Particular focus is given to systems with limited experimentally measured superconductivity information such as europium.;Total energy and density of states information from first-principles electronic structure calculations have been used as input to the McMillan equation to determine the parameters that control superconductivity. The electron-phonon coupling lambda has been determined by using the rigid muffin-tin approximation (RMTA) and density functional theory. The calculated electronic, structural, and superconductivity properties generally agree well with experiment.