Towards higher-Tc superconductors.

New superconductors discovered in the Akimitsu laboratory are reviewed here. These materials can be categorized into two groups:1) Cu-oxide superconductors.1-1 Cu-oxide system having CuO2 planes.1-2 Ladder lattice superconductor.2) Exploration of new metal-based superconductors.2-1 MgB2 and its application.2-2 Y2C3.2-3 Carrier-doped wide-gap semiconductors.2-4 New superconductor with a cage-type structure: R5T6Sn18 (R = Sc, Y, Lu; T = Rh, Ir).Finally, all of the new superconductors discovered in our laboratory are summarized. The outlook for the high-Tc superconductors and our present work are also described.