Cuprate

Cuprate loosely refers to a material that can be viewed as containing copper anions. Examples include tetrachloridocuprate ([CuCl₄]²⁻), the superconductor YBa₂Cu₃O₇, and the organocuprates ([Cu(CH₃)₂]⁻). The term cuprates derives from the Latin word for copper, cuprum. The term is mainly used in three contexts - oxide materials, anionic coordination complexes, and anionic organocopper compounds.

Oxides

One of the simplest oxide-based cuprates is the copper(III) oxide KCuO₂, a dark blue diamagnetic solid. It is produced by heating potassium peroxide and copper(II) oxide in an atmosphere of oxygen:

Interest in cuprates sharply increased in 1986 with the discovery of high-temperature superconductivity in the Non-stoichiometric cuprate lanthanum barium copper oxide La_2-xBa_xCuO₄. The T_c for this material was 35 K, well above the previous record of 23K. Thousands of publications examine the superconductivity in cuprates between 1986 and 2001, and Bednorz and Müller were awarded the Nobel Prize in Physics only a year after their discovery.