This book presents an overview of material-specific factors that influence T_c and give rise to diverse T_c values for copper oxides and iron-based high- T_c superconductors on the basis of more than 25 years of experimental data, to most of which the author has made important contributions. The book then explains why both compounds are distinct from others with similar crystal structure and whether or not one can enhance T_c, which in turn gives a hint on the unresolved pairing mechanism. This is an unprecedented new approach to the problem of high-temperature superconductivity and thus will be inspiring to both specialists and non-specialists interested in this field.
Readers will receive in-depth information on the past, present, and future of high-temperature superconductors, along with special, updated information on what the real highest T_c values are and particularly on the possibility of enhancing T_c for each member material, which is important for application. At this time, the highest T_c has not been improved for 20 years, and no new superconductors have been discovered for 5 years. This book will encourage researchers as well as graduate-course students not to give up on the challenges in the future of high- T_c superconductivity.