This book presents current research from across the globe in the study of superconductivity theory, materials and applications. Topics discussed include tunnelling spectroscopy of novel layered superconductors; stability conditions of high-Tc superconductors; a study of the superconducting phase in metallic superconductors; numerical calculation of trapped magnetic field for bulk superconductors; ion modified high-Tc Josephson junctions and SQUIDS; and, vortices in high temperature superconductors.