High-temperature superconducting materials: A decade of impressive advancement of T_c

In the decade after the discovery of high-temperature superconductivity, more than one hundred non-intermetallic compounds have been found to superconduct above 23 K, which is the record transition temperature (T_c) of conventional low-temperature intermetallic superconductors. These high-temperature non-intermetallic superconductors belong to three compound families: the cuprates, the bismuthades, and the fullerites. In this presentation, I shall restrict myself to the cuprates with a Tc above the liquid nitrogen boiling point of 77 K. They show a current record T_c of 134 K at ambient and 164 K at high pressure. I shall recall events that led to the discovery of superconductivity at 93 K to bring down the 77 K temperature barrier and summarize subsequent efforts to raise the T_c to its present record. Prospects for future higher T_c will be discussed.