Five questions dominated the ARW on Physics and Materials Science of
High Temperature Superconductors, of which this book forms the
permanent record. Briefly, these are: (i) How close are we to a unified
theory? The consensus is that we are not. (ii) Flux pinning: can it be
achieved in bulk materials? Still an open question. The following three
questions are related. (iii) Can grain boundary contributions be brought
under control? (iv) What is the real requirement for purity and general
chemistry control? (v)What is the practical outlook for bulk products -
tapes and wires? One of the conclusions is that the geometry and
dimensions in thin films are the key parameters that facilitate the
realization of high current densities and, consequently, their
commercial application. On the other hand, the very large number of
poorly understood microstructural, chemical and mechanical variables
involved in the preparation of bulk materials are currently prohibiting
large scale commercialization of wires and tapes.