Quaternary phase

YBa2Cu3O7, abbreviated YBCO is a famous quaternary phase. It features four elements: yttrium (Y), barium (Ba), copper (Cu), and oxygen (O).

In materials chemistry, a quaternary phase is a chemical compound containing four elements. Some compounds can be molecular or ionic, examples being chlorodifluoromethane (CHClF2) and sodium bicarbonate (NaCO3H). More typically quaternary phase refers to extended solids. A famous example are the yttrium barium copper oxide superconductors.[1]

  1. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.