Quaternary phase

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.

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

See also

• Binary compound
• Ternary compound